WL#14189: Replace old terms in CHANGE MASTER TO and START SLAVE params

# EXECUTIVE SUMMARY

This worklog implements aliases for CHANGE MASTER and its parameters and for
START REPLICA/SLAVE parameters as well. The alias introduced for CHANGE MASTER
is CHANGE REPLICATION SOURCE. Parameters with MASTER in their name get an alias
that replaces MASTER with SOURCE. If the old terminology is used, deprecation
warnings are emitted.

# USER/DEV STORIES

As a MySQL admin user I want to issue replication commands that do not
contain offensive terms so that I do not get offended by them and/or
expose them to other people (e.g., customers of my application built
on top of MySQL).

# SCOPE

This worklog is part of a broader effort to change old terminology
across the entire MySQL product line. However, this worklog focuses
only on changing the terminology for the following commands/SQL
statements:

- CHANGE MASTER and its parameters.
- START REPLICA parameters names.

# LIMITS

N/A

# REFERENCES

- https://mysqlhighavailability.com/mysql-terminology-updates/

FR1. CHANGE REPLICATION SOURCE shall execute 100% the same actions that
     CHANGE MASTER does.

FR2. CHANGE MASTER and CHANGE REPLICATION SOURCE shall accept aliases
     for all their parameters having MASTER in their names. The alias
     shall have MASTER replaced by SOURCE.

FR2. START REPLICA/SLAVE UNTIL SOURCE_LOG_POS, SOURCE_LOG_FILE shall execute
     100% the same actions that START REPLICA UNTIL MASTER_LOG_POS,
     MASTER_LOG_FILE does.

FR3. CHANGE REPLICATION SOURCE statement shall emit one deprecation
     warning per old term used. This applies to CHANGE MASTER and also
     its parameters, meaning that "CHANGE MASTER TO MASTER_HOST='...',
     MASTER_PORT=N" SHALL emit 3 deprecation warnings.

FR4. START REPLICA/SLAVE UNTIL shall emit one deprecation warning per
     old term used.

# SUMMARY OF THE APPROACH

- We create aliases for CHANGE MASTER parameters with MASTER in their
  name. The aliases contain SOURCE instead of MASTER in the name.

- We create a new alias for CHANGE MASTER: CHANGE REPLICATION SOURCE.

- We create aliases for START REPLICA/SLAVE UNTIL MASTER_LOG_POS and
  MASTER_LOG_FILE. User can now use SOURCE_LOG_POS and SOURCE_LOG_FILE
  instead.

- We emit deprecation warnings whenever an old term is used.

# SECURITY CONTEXT

No security implications.

# UPGRADE/DOWNGRADE and CROSS-VERSION REPLICATION

## New Statements

New statements will be introduced to replace old statements.

There are no upgrade/downgrade or cross-version replication implications, except
for the fact that statements being replaced will now emit deprecation warnings.

# USER INTERFACE

## Alias for old statements

- CHANGE MASTER -> CHANGE REPLICATION SOURCE
- MASTER_AUTO_POSITION -> SOURCE_AUTO_POSITION
- MASTER_HOST -> SOURCE_HOST
- MASTER_BIND -> SOURCE_BIND
- MASTER_USER -> SOURCE_USER
- MASTER_PASSWORD -> SOURCE_PASSWORD
- MASTER_PORT -> SOURCE_PORT
- MASTER_CONNECT_RETRY -> SOURCE_CONNECT_RETRY
- MASTER_RETRY_COUNT -> SOURCE_RETRY_COUNT
- MASTER_DELAY -> SOURCE_DELAY
- MASTER_SSL -> SOURCE_SSL
- MASTER_SSL_CA -> SOURCE_SSL_CA
- MASTER_SSL_CAPATH -> SOURCE_SSL_CAPATH
- MASTER_SSL_CIPHER -> SOURCE_SSL_CIPHER
- MASTER_SSL_CRL -> SOURCE_SSL_CRL
- MASTER_SSL_CRLPATH -> SOURCE_SSL_CRLPATH
- MASTER_SSL_KEY -> SOURCE_SSL_KEY
- MASTER_SSL_VERIFY_SERVER_CERT -> SOURCE_SSL_VERIFY_SERVER_CERT
- MASTER_TLS_VERSION -> SOURCE_TLS_VERSION
- MASTER_TLS_CIPHERSUITES -> SOURCE_TLS_CIPHERSUITES
- MASTER_SSL_CERT -> SOURCE_SSL_CERT
- MASTER_PUBLIC_KEY_PATH -> SOURCE_PUBLIC_KEY_PATH
- GET_MASTER_PUBLIC_KEY -> GET_SOURCE_PUBLIC_KEY
- MASTER_HEARTBEAT_PERIOD -> SOURCE_HEARTBEAT_PERIOD
- MASTER_COMPRESSION_ALGORITHM -> SOURCE_COMPRESSION_ALGORITHM
- MASTER_ZSTD_COMPRESSION_LEVEL -> SOURCE_ZSTD_COMPRESSION_LEVEL
- MASTER_LOG_FILE -> SOURCE_LOG_FILE
- MASTER_LOG_POS -> SOURCE_LOG_POS

## Deprecation warnings

- Deprecation warnings will be emited when old terminology is used in
  the CHANGE MASTER/REPLICATION SOURCE and START REPLICA/SLAVE statements.

# OBSERVABILITY

## Status Variables Change

An alias for the following status variable is introduced.

- Com_change_master = Com_change_replication_source

This introduces a new status variable. This means that SHOW GLOBAL STATUS
shall output one more variable (which is an alias to an existing one).
Therefore tools that regularly scan status variables will get a new status
var in the result set.

Note that NO deprecation warning is emitted when SHOW VARIABLES LIKE
'Com_change_master' is issued, but it will be deprecated in the documentation.

## BUILD, DEPLOY and INSTALL

Nothing worth noting.

## PROTOCOL

No protocol implications.

## FAILURE MODEL SPECIFICATION

No changes to the failure model.

## PERFORMANCE AND EFFICIENCY

No performance implication.

# DESIGN IMPLEMENTATION STEPS

1. Change the parser to add an alias for the MASTER symbol when used
   in the CHANGE MASTER command.

2. Change the parser to add aliases for the parameters of CHANGE
   MASTER.

3. Deploy deprecation warnings to the parser when using old terms in
   CHANGE REPLICATION SOURCE and START REPLICA UNTIL.

4. Change the test suite to use the new syntax and thus avoid the
   deprecation warnings.