MDEV-32203 Raise notes when an index cannot be used on data type mismatch

Raise notes if indexes cannot be used:
- in case of data type or collation mismatch (diferent error messages).
- in case if a table field was replaced to something else
  (e.g. Item_func_conv_charset) during a condition rewrite.

Added option to write warnings and notes to the slow query log for
slow queries.

New variables added/changed:

- note_verbosity, with is a set of the following options:
  basic            - All old notes
  unusable_keys    - Print warnings about keys that cannot be used
                     for select, delete or update.
  explain          - Print unusable_keys warnings for EXPLAIN querys.

The default is 'basic,explain'. This means that for old installations
the only notable new behavior is that one will get notes about
unusable keys when one does an EXPLAIN for a query. One can turn all
of all notes by either setting note_verbosity to "" or setting sql_notes=0.

- log_slow_verbosity has a new option 'warnings'. If this is set
  then warnings and notes generated are printed in the slow query log
  (up to log_slow_max_warnings times per statement).

- log_slow_max_warnings   - Max number of warnings written to
                            slow query log.

Other things:
- One can now use =ALL for any 'set' variable to set all options at once.
  For example using "note_verbosity=ALL" in a config file or
  "SET @@note_verbosity=ALL' in SQL.
- mysqldump will in the future use @@note_verbosity=""' instead of
  @sql_notes=0 to disable notes.
- Added "enum class Data_type_compatibility" and changing the return type
  of all Field::can_optimize*() methods from "bool" to this new data type.

Reviewer & Co-author: Alexander Barkov <bar@mariadb.com>
- The code that prints out the notes comes mainly from Alexander

mysql-test/main/mysqld--help.result

@@ -210,6 +210,7 @@ The following specify which files/extra groups are read (specified before remain
  Default flags for the regex library. Any combination of: 
  DOTALL, DUPNAMES, EXTENDED, EXTENDED_MORE, EXTRA, 
  MULTILINE, UNGREEDY
+ Use 'ALL' to set all combinations.
  --default-storage-engine=name 
  The default storage engine for new tables
  --default-time-zone=name 
@@ -484,12 +485,14 @@ The following specify which files/extra groups are read (specified before remain
  --log-disabled-statements=name 
  Don't log certain types of statements to general log. Any
  combination of: slave, sp
+ Use 'ALL' to set all combinations.
  --log-error[=name]  Log errors to file (instead of stdout).  If file name is
  not specified then 'datadir'/'log-basename'.err or the
  'pid-file' path with extension .err is used
  --log-isam[=name]   Log all MyISAM changes to file.
  --log-output=name   How logs should be written. Any combination of: NONE, 
  FILE, TABLE
+ Use 'ALL' to set all combinations.
  --log-queries-not-using-indexes 
  Log queries that are executed without benefit of any
  index to the slow log if it is open. Same as
@@ -508,15 +511,20 @@ The following specify which files/extra groups are read (specified before remain
  --log-slow-disabled-statements=name 
  Don't log certain types of statements to slow log. Any
  combination of: admin, call, slave, sp
+ Use 'ALL' to set all combinations.
  --log-slow-filter=name 
  Log only certain types of queries to the slow log. If
- variable empty alll kind of queries are logged.  All
- types are bound by slow_query_time, except
- 'not_using_index' which is always logged if enabled. Any
- combination of: admin, filesort, filesort_on_disk, 
+ variable empty all kind of queries are logged.  All types
+ are bound by slow_query_time, except 'not_using_index'
+ which is always logged if enabled. Any combination of: 
+ admin, filesort, filesort_on_disk, 
  filesort_priority_queue, full_join, full_scan, 
  not_using_index, query_cache, query_cache_miss, tmp_table,
  tmp_table_on_disk
+ Use 'ALL' to set all combinations.
+ --log-slow-max-warnings=# 
+ Max numbers of warnings printed to slow query log per
+ statement
  --log-slow-rate-limit=# 
  Write to slow log every #th slow query. Set to 1 to log
  everything. Increase it to reduce the size of the slow or
@@ -528,7 +536,8 @@ The following specify which files/extra groups are read (specified before remain
  (Defaults to on; use --skip-log-slow-slave-statements to disable.)
  --log-slow-verbosity=name 
  Verbosity level for the slow log. Any combination of: 
- innodb, query_plan, explain, engine, full
+ innodb, query_plan, explain, engine, warnings, full
+ Use 'ALL' to set all combinations.
  --log-tc=name       Path to transaction coordinator log (used for
  transactions that affect more than one storage engine,
  when binary log is disabled).
@@ -646,6 +655,7 @@ The following specify which files/extra groups are read (specified before remain
  Specifies how corrupted tables should be automatically
  repaired. Any combination of: DEFAULT, BACKUP, FORCE, 
  QUICK, BACKUP_ALL, OFF
+ Use 'ALL' to set all combinations.
  --myisam-repair-threads=# 
  If larger than 1, when repairing a MyISAM table all
  indexes will be created in parallel, with one thread per
@@ -674,6 +684,11 @@ The following specify which files/extra groups are read (specified before remain
  --net-write-timeout=# 
  Number of seconds to wait for a block to be written to a
  connection before aborting the write
+ --note-verbosity=name 
+ Verbosity level for note-warnings given to the user. See
+ also @@sql_notes.. Any combination of: basic, 
+ unusable_keys, explain
+ Use 'ALL' to set all combinations.
  --old               Use compatible behavior from previous MariaDB version.
  See also --old-mode
  --old-alter-table[=name] 
@@ -684,6 +699,7 @@ The following specify which files/extra groups are read (specified before remain
  MySQL versions. Any combination of: 
  NO_DUP_KEY_WARNINGS_WITH_IGNORE, NO_PROGRESS_INFO, 
  ZERO_DATE_TIME_CAST, UTF8_IS_UTF8MB3
+ Use 'ALL' to set all combinations.
  --old-passwords     Use old password encryption method (needed for 4.0 and
  older clients)
  --old-style-user-limits 
@@ -1284,6 +1300,7 @@ The following specify which files/extra groups are read (specified before remain
  variable is empty, no conversions are allowed and it is
  expected that the types match exactly. Any combination
  of: ALL_LOSSY, ALL_NON_LOSSY
+ Use 'ALL' to set all combinations.
  --slow-launch-time=# 
  If creating the thread takes longer than this value (in
  seconds), the Slow_launch_threads counter will be
@@ -1314,6 +1331,7 @@ The following specify which files/extra groups are read (specified before remain
  NO_ENGINE_SUBSTITUTION, PAD_CHAR_TO_FULL_LENGTH, 
  EMPTY_STRING_IS_NULL, SIMULTANEOUS_ASSIGNMENT, 
  TIME_ROUND_FRACTIONAL
+ Use 'ALL' to set all combinations.
  --sql-safe-updates  If set to 1, UPDATEs and DELETEs need either a key in the
  WHERE clause, or a LIMIT clause, or else they will
  aborted. Prevents the common mistake of accidentally
@@ -1421,6 +1439,7 @@ The following specify which files/extra groups are read (specified before remain
  --time-format=name  The TIME format (ignored)
  --tls-version=name  TLS protocol version for secure connections.. Any
  combination of: TLSv1.0, TLSv1.1, TLSv1.2, TLSv1.3
+ Use 'ALL' to set all combinations.
  --tmp-disk-table-size=# 
  Max size for data for an internal temporary on-disk
  MyISAM or Aria table.
@@ -1601,6 +1620,7 @@ log-slave-updates FALSE
 log-slow-admin-statements TRUE
 log-slow-disabled-statements sp
 log-slow-filter admin,filesort,filesort_on_disk,filesort_priority_queue,full_join,full_scan,query_cache,query_cache_miss,tmp_table,tmp_table_on_disk
+log-slow-max-warnings 10
 log-slow-rate-limit 1
 log-slow-slave-statements TRUE
 log-slow-verbosity 
@@ -1655,6 +1675,7 @@ net-buffer-length 16384
 net-read-timeout 30
 net-retry-count 10
 net-write-timeout 60
+note-verbosity basic,explain
 old FALSE
 old-alter-table DEFAULT
 old-mode UTF8_IS_UTF8MB3