Inclusive Naming: replace SHOW SLAVE STATUS with SHOW REPLICA STATUS

[deepthi]

Once MySQL 5.7 is EOL (late 2023) and we drop support, we will be able to replace the replication commands with new ones (available in. 8.0.22+)
Unfortunately we will need to continue to use SHOW MASTER STATUS and CHANGE MASTER TO unless those have new equivalents by then.

[mattlord]

Another alternative — that I think is clearly better, but would require a new project on our side — is to use the performance_schema replication tables instead. The master and slave terminology is already gone there.

MariaDB is significantly different here but I'm also proposing that we deprecate support for MariaDB in #9518 and the timing would align.

[mw491605]

你

[deepthi]

It's not just SHOW, we also have START, RESET etc.
We should keep it simple and not bring in select from performance_schema into this path.
It occurs to me that because we already have two flavors for MySQL - 5.7 and 8.0, we can go ahead and make the changes for the 8.0 flavor now, no need to wait for 5.7 EOL. When 5.7 does EOL, we can simply delete that flavor.

[GuptaManan100]

We'll do this in v19.0.0 because we will drop support for MySQL 5.7 after v18