Use names already supported by our tools

[robholland]

What was changed

Deprecated some variable names in favour of clearer alternatives.

Why?

This avoids naming that is confusing users new to deploying Temporal, and reduces the amount of mapping needed between the environment and our tools (which already accept the environment variables I'm proposing we use here).

As an added small bonus we get full connection attribute support rather than just MySQL transaction isolation.

The rollout plan would be:

1. Update our docker config template to support the new variables as-is in our container images, this needs to happen before this PR is merged.
2. Remove the deprecation message for now, but keep the auto-migration
3. Update our docker-compose files and internal systems to use the new variables
4. Turn on the deprecation messages.
5. After some time, remove the old variables.

Note that the auto-setup.sh script only supports changing the database name between persistence and visibility configurations. Our config template supports a wider range of visibility overrides, which we should also support in auto-setup.sh. This PR does not attempt to address that now though, and rather aims to keep functionality the same, aside from the connection attribute support mentioned above.

Checklist

1. Closes

2. How was this tested:

8. Any docs updates needed?