This reverts commit several commits pushed by mistake.

Workaround Windows' bug in services "ANSI" when process ANSI codepage is
UTF8.
They turn out to work unlike any other API .

Expected behavior : strings  be converted from GetACP() to Unicode,
and "wide" function would be then called.

Actual current behavior :
it seems to handle strings as-if they would be encoded in system-default
ACP, rather than process-specific GetACP()

Fix: redefine the OpenService,CreateService and ChangeServiceConfig
and do ANSI-Wide conversion outselves.

Tell compiler to deprecate some ANSI service functions.

xxx

- allow utf8 datadir, and password
- mysql_install_db.exe does not send clear password to mysqld --bootstrap
  subprocess anymore, but hash, as server makes incorrect assumption about
  character encoding in case it is UTF8.
- use CreateServiceW to create service, due to some Windows bug,
  the ANSI version does not currently work well with strings outside
  of ASCII range.

Many recent PRs offer up shell scripts or example queries in the testing
section, when these could be easily and usefully be converted to automated
tests based on MTR.  (https://github.com/MariaDB/server/pull/1888 and
https://github.com/MariaDB/server/pull/1940 are good examples of this.)

This modifies the PR template to more strongly encourage the contribution of
automated tests.

Upon investigation, decided this to be a compiler bug
(happens with new compiler, on code that did not change for the last 15 years)

Fixed by de-optimizing single function remove_key(), using MSVC pragma

In dict_index_t::clear(), InnoDB frees all the page except root page.
root page leaf segment has reset and does reinitialize again.
t in fseg_create(), we do have the assumption that only
FIL_PAGE_TYPE_TRX_SYS or FIL_PAGE_TYPE_TRX_SYS page should
be re-created for non-full-crc32 format. This assumption is wrong
in case of rollback of bulk insert operation.

MDEV-27006 Assertion `!lock_trx_has_sys_table_locks(trx)' failed in dberr_t row_discard_tablespace_for_mysql(dict_table_t*, trx_t*)

- InnoDB import operation fails when it tries to unlock data
dictionary lock before releasing the lock on system tables.

The debug assertion that was added in
commit 9b967c4c
tripped Valgrind and MemorySanitizer.

buf_block_init(): Assert that block->page.hash was zero-initialized.

This fixes up commit d22c8cae

The previous threads locked need to be released too.

This occurs if the initialization of any of the non-first
mutex/conditition variables errors occurs.

Fix a bug of unreleased lock ctrl_mutex in the method create_worker_threads

added summary/description per package.