Adding feature to postgres returner to save minion which are expected to return for a job

[arunkpj122]

What does this PR do?

This PR enables the PostgreSQL returner to store expected minion IDs for a job within the returner, ensuring that the returner correctly reports missing minions when missing=True is used.

What issues does this PR fix or reference?

While using the PostgreSQL returner to store job caches, salt_returns, and salt_events in a PostgreSQL database, the following issue arises:

When executing a command in --async mode, we receive a Job ID (JID). To track the progress of this JID, we run:

salt-run jobs.lookup_jid <JID> missing=True

We expect this command to return "minion did not return" for any minions that have not yet responded. However, this is not happening—no output is provided for minions that haven't returned.

This functionality works correctly when we remove the PostgreSQL returner configuration and use the local job cache instead.

Salt-user group discussion link: https://groups.google.com/g/salt-users/c/eN6mvymi1qA

New Behavior

With the raised enhancement, the PostgreSQL returner is now able to save minion IDs correctly and accurately detect which minions have returned and which have not.

Merge requirements satisfied?

[NOTICE] Bug fixes or features added to Salt require tests.

• Docs
• Changelog - https://docs.saltproject.io/en/master/topics/development/changelog.html
• Tests written/updated

Commits signed with GPG?

No

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[dmurphy18]

Needs a changelog entry and tests written in pytest which exercises the code changes