release-24.1: pgwire: log session start and end unconditionally

[blathers-crl]

Backport 3/3 commits from #124254 on behalf of @rafiss.

/cc @cockroachdb/release

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pgwire: remove redundant log for JWT auth

This already gets logged in the processCommands function, right before
the server enters the main command processing loop.

pgwire: log auth info message as redactable string

Previously, the entire info text would be redacted, which made
debugging harder. This improves it so we use the built in
redaction facilities in order to get more detail.

pgwire: log session start and end unconditionally

Release note (ops change): The client_authentication_ok and
client_session_end messages are now logged to the SESSIONS log channel
unconditionally. Previously, these would only be logged if the
server.auth_log.sql_sessions.enabled cluster setting was changed to
true. All other SESSIONS log messages are still only logged if
server.auth_log.sql_sessions.enabled or
server.auth_log.sql_connections.enabled are set to true.

If you do not want to see client_authentication_ok or client_session_end
messages, then the SESSIONS log channel can be disabled entirely.

fixes #122684

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Release justification: high value logging change

[blathers-crl]

Thanks for opening a backport.

Please check the backport criteria before merging:

• Backports should only be created for serious
  issues or test-only changes.
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• There is a high priority need for the functionality that cannot wait until the next release and is difficult to address in another way.
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Also, please add a brief release justification to the body of your PR to justify this
backport.

[blathers-crl]

It looks like your PR touches production code but doesn't add or edit any test code. Did you consider adding tests to your PR?

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[cockroach-teamcity]

This change is