MDEV-16421 Make system tables crash safe

Make all system tables in mysql directory of type
engine=Aria

Privilege tables are using transactional=1
Statistical tables are using transactional=0, to allow them
to be quickly updated with low overhead.
Help tables are also using transactional=0 as these are only
updated at init time.

Other changes:
- Aria store engine is now a required engine
- Update comment for Aria tables to reflect their new usage
- Fixed that _ma_reset_trn_for_table() removes unlocked table
  from transaction table list. This was needed to allow one
  to lock and unlock system tables separately from other
  tables, for example when reading a procedure from mysql.proc
- Don't give a warning when using transactional=1 for engines
  that is using transactions. This is both logical and also
  to avoid warnings/errors when doing an alter of a privilege
  table to InnoDB.
- Don't abort on warnings from ALTER TABLE for changes that
  would be accepted by CREATE TABLE.
- New created Aria transactional tables are marked as not movable
  (as they include create_rename_lsn).
- bootstrap.test was changed to kill orignal server, as one
  can't anymore have two servers started at same time on same
  data directory and data files.
- Disable maria.small_blocksize as one can't anymore change
  aria block size after system tables are created.
- Speed up creation of help tables by using lock tables.
- wsrep_sst_resync now also copies Aria redo logs.

mysql-test/suite/innodb_zip/r/index_large_prefix.result

@@ -337,7 +337,7 @@ create index idx4 on worklog5743(a1, a2);
 ERROR 42000: Specified key was too long; max key length is 3072 bytes
 show warnings;
 Level	Code	Message
-Error	1071	Specified key was too long; max key length is 3072 bytes
+Warning	1071	Specified key was too long; max key length is 3072 bytes
 Error	1071	Specified key was too long; max key length is 3072 bytes
 create index idx5 on worklog5743(a1, a5);
 ERROR 42000: Specified key was too long; max key length is 3072 bytes