Reload PostgreSQL configuration when Patroni is enabled

What does this MR do?

This MR ensures that subsequent changes to PostgreSQL configuration, including pg_hba.conf, pg_ident.conf, and runtime.conf, will be reloaded when gitlab-ctl reconfigure is invoked.

How to test it?

1. Deploy a Patroni cluster (you can use https://gitlab.com/pursultani/gitlab-patroni-test).
2. Change postgresql[...], including postgresql['trust_auth_cidr_addresses'] or postgresql['md5_auth_cidr_addresses'], which will be reflected in pg_hba.conf, pg_ident.conf, postgresql.conf, or runtime.conf.
3. Reconfigure the nodes. gitlab-ctl reconfigure must print out the output patronictl reload which means the node is reloaded.
4. Check Patroni service logs. It must show that PostgreSQL received SIGHUP (it may take a few seconds < 10s).
5. Check the Patroni cluster. The leader and replicas must not change as a result of the reconfiguration.

Related issues

Closes #5616 (closed)

Checklist

See Definition of done.

For anything in this list which will not be completed, please provide a reason in the MR discussion

Required

• Merge Request Title, and Description are up to date, accurate, and descriptive
• MR targeting the appropriate branch
• MR has a green pipeline on GitLab.com
• Pipeline is green on dev.gitlab.org if the change is touching anything besides documentation or internal cookbooks
• trigger-package has a green pipeline running against latest commit

Expected (please provide an explanation if not completing)

• Test plan indicating conditions for success has been posted and passes
• Documentation created/updated
• Tests added
• Integration tests added to GitLab QA
• Equivalent MR/issue for the GitLab Chart opened