Hiding the definitions inside Type_handler_xxx::name().

This is needed to avoid exporting members with MYSQL_PLUGIN_IMPORT,
which would be needed to compile data type plugins on Windows.

Introducing methods instead:
  const Name version_mysql56() const;
  const Name version_mariadb53() const;

This is needed to avoid exporting members with MYSQL_PLUGIN_IMPORT,
which would be needed to compile data type plugins on Windows.

Command COM_SHUTDOWN was rejected in non-Primary because
server_command_flags[COM_SHUTDOWN] had value CF_NO_COM_MULTI
instead of CF_SKIP_WSREP_CHECK.

As a fix removed assignment
server_command_flags[CF_NO_COM_MULTI]= CF_NO_COM_MULTI
which overwrote server_command_flags[COM_SHUTDOWN].

MDEV-20228 `mysql_upgrade` fails on every version upgrade: "ERROR 1267 (HY000) at line 7: Illegal mix of collations (utf8mb4_unicode_ci,COERCIBLE) and (utf8mb4_general_ci,COERCIBLE) for operation 'like'"

MDEV-18153 Assertion `0' or Assertion `btr_validate_index(index, 0)' failed in row_upd_sec_index_entry or error code 126: Index is corrupted upon UPDATE with TIME_ROUND_FRACTIONAL

Conversion to a temporal data type resulting into a lower precision
depends on TIME_ROUND_FRACTIONAL. Taking into account this dependency in:
- indexed generated virtual column expressions
- persistent virtual column expressions

A warning is now issued if conversion from the generation expression
to the column data type depends on TIME_ROUND_FRACTIONAL.

The warning will be changed to error in 10.5

Followup patch: fix typos

Follow-up to 9d26f3da:
do not declare a never-overloaded function as virtual.

Closes PR #1385

Rerecord the result file. It was caused by MDEV-20477(967c14c0)

innobase_rename_or_enlarge_column_try(): Relax a debug assertion.
The DATA_VERSIONED bits in dict_col_t::prtype do not affect the
storage format.

Fixed 4-byte length characters handled incorrectly.

Rerecord sysvars_server_notembedded

Problem was that if user used bad wsrep configuration
we call unireg_abort and in wsrep case there is check
to wsrep_server_state that might not yet be initialized.
Fixed by checking that wsrep_server_state is initialized
before checking it's state.

Changes to be committed:
	modified:   sql/mysqld.cc
	modified:   sql/wsrep_server_state.h

In mysql-server/commit@f46329044f8618212923bdf52e15d5b464201edc
the InnoDB function btr_cur_open_at_rnd_pos() was corrected so that
it would return a status that indicates whether the cursor was
successfully positioned. But this change was not correctly merged to
MariaDB in 2e814d47.

btr_cur_open_at_rnd_pos(): In the code path that was introduced in
MDEV-8588, properly return failure status.

No deterministic test case was found for this failure.
It was caught after removing the function
page_copy_rec_list_end_to_created_page() in a development branch.
As a result, the fill factor of index trees would improve, and
supposedly, so would the probability of btr_cur_open_at_rnd_pos()
reaching the intentionally corrupted page in the test
innodb.leaf_page_corrupted_during_recovery.
The wrong return value would cause
btr_estimate_number_of_different_key_vals() to wrongly invoke
btr_rec_get_externally_stored_len() on a non-leaf page and
trigger an assertion failure at the start of that function.

- During trx_undo_report_rename(), InnoDB can fail to write undo log
for it if undo log doesn't fit in the undo page. In that case, InnoDB
adds one more undo log page and retry to write the rename undo log.
But the assert is wrong and it doesn't allow to fail even for one time.

Revert "Part3: MDEV-18156 Assertion `0' failed or `btr_validate_index(index, 0, false)' in row_upd_sec_index_entry or error code 126: Index is corrupted upon DELETE with PAD_CHAR_TO_FULL_LENGTH"

This reverts commit 5a9e2b77 in 10.5,
so it produces an error on "bad" generated columns.

Note, 10.2, 10.3, 10.4 produce only warnings, for backward compatibility.

Cherry-pick the commits the mysql and some changes.
WL#4618 RBR: extended table metadata in the binary log

This patch extends Table Map Event. It appends some new fields for
more metadata. The new metadata includes:
- Signedness of Numberic Columns
- Character Set of Character Columns and Binary Columns
- Column Name
- String Value of SET Columns
- String Value of ENUM Columns
- Primary Key
- Character Set of SET Columns and ENUM Columns
- Geometry Type

Some of them are optional, the patch introduces a GLOBAL system
variable to control it. It is binlog_row_metadata.
- Scope:   GLOBAL
- Dynamic: Yes
- Type:    ENUM
- Values:  {NO_LOG, MINIMAL, FULL}
- Default: NO_LOG
  Only Signedness, character set and geometry type are logged if it is MINIMAL.
  Otherwise all of them are logged.

Also add a binlog_type_info() to field, So that we can have extract
relevant binlog info from field.

Null merge the MDEV-14383 fix; it affects 5.5 only.