Resize the types and widths of SHOW REPLICA STATUS
(technically `INFORMATION_SCHEMA.SLAVE_STATUS`)
columns to better match their possible values
In case of intentionally but absurdly long lists,
text columns that list an uncapped number of elements
have expanded to accept as many bytes as we could support.
Particularly, the first-gen `Replicate_` filters were
incorrectly typed as singlular `Name()`s during MDEV-33526.
Under `Name`s’ 64-char limit, they could overflow
(read: truncate) even before their lengths got absurd.
In response to `‘MAX_SLAVE_ERRMSG’ was not declared in this scope` in
Embedded builds, a new `#ifdef HAVE_REPLICATION` guard wraps
`slave_status_info` to skip this unused data in Replication-less builds.
For testing, this commit forward-ports a modified cherry-pick of #3795
(the latter targets our oldest maintained LTS as part of MDEV-35948).
> Assert that 1st-gen `replicate_*` filter variables display
> their input – including long but reasonable lists –
> correctly (without truncation) in
> * direct SELECT
> * [semi-new] INFORMATION_SCHEMA.GLOBAL_VARIABLES.VARIABLE_VALUE
> * [new] SHOW REPLICA STATUS
Reviewed-by: Brandon Nesterenko <brandon.nesterenko@mariadb.com>
Make the slave options --replicate-* dynamic variables so that these
options can be changed dynamically while the server is running,
which enables users to modify replication filtering rules without
having to stop and restart the server.
This is accomplished by just requiring that the slave threads are
stopped when these options are set dynamically. Since filtering
rules are only used by the SQL slave thread, setting them while the
thread is not running avoids the need for locking.
