MDEV-19940 Clean up INFORMATION_SCHEMA.INNODB_ tables

Shorten some VARCHAR attributes to a more reasonable length.

INNODB_METRICS: Rename the column STATUS to ENABLED, and make it Boolean.

Replace with INT(1) many Boolean attributes that were declared as VARCHAR
containing 'NO','YES','disabled','enabled','Uninitialized','Initialized'.

Replace some VARCHAR attributes with ENUM.

Replace some BIGINT with INT when 32 bits are sufficient.

Remove INNODB_SYS_TABLESPACES.SPACE_TYPE. The type of a tablespace
can be derived from the tablespace ID. A fixed number is used for
the system tablespace and the temporary tablespace. All other tablespaces
are single-table or single-partition tablespaces.

i_s_locks_row_t::lock_type, lock_get_type_str(): Remove.
This is a redundant field. Table and record locks can be
distinguished by whether i_s_locks_row_t::lock_index is NULL.

fill_trx_row(): Do not unnecessarily copy the constant strings that
trx->op_info is pointing to.

i_s_locks_row_t::lock_mode: Replace string with integer.

lock_get_mode_str(), lock_get_trx_id(), lock_get_trx(): Remove.

field_store_ulint(): Remove.

mysql-test/suite/innodb/include/show_i_s_tablespaces.inc

@@ -6,7 +6,6 @@
 --replace_regex  /#P#/#p#/  /#SP#/#sp#/
 --replace_result ./ MYSQLD_DATADIR/  $MYSQLD_DATADIR/ MYSQLD_DATADIR/  $MYSQLD_DATADIR MYSQLD_DATADIR/  $MYSQL_TMP_DIR MYSQL_TMP_DIR  $INNODB_PAGE_SIZE DEFAULT
 SELECT s.name 'Space_Name',
-	s.space_type 'Space_Type',
 	s.page_size 'Page_Size',
 	s.zip_page_size 'Zip_Size',
 	s.row_format 'Formats_Permitted',