Remove permanent dedicated repo host and make archiving to cloud repo…

[dsessler7]

…s go through pg instance. This essentially reverts commit cfa2839.

Clean up some markdown files.
Add test case for pgbackrest conf files when cloud repo present but no dedicated repo host present.

Checklist:

• Have you added an explanation of what your changes do and why you'd like them to be included?
• Have you updated or added documentation for the change, as applicable?
• Have you tested your changes on all related environments with successful results, as applicable?
  • Have you added automated tests?

Type of Changes:

• New feature
• Bug fix
• Documentation
• Testing enhancement
• Other

What is the current behavior (link to any open issues here)?

Currently, a dedicated repo host will be created whether a local volume repo is defined and all archiving is done through the dedicated repo host. This is a single point of failure for our disaster recovery solution.

What is the new behavior (if this is a feature change)?

• Breaking change (fix or feature that would cause existing functionality to change)

This change makes it so a dedicated repo host is only created when a local volume repo is defined and changes archiving for cloud repos to go through the pg instance. This change essentially reverts the commit cfa2839 which was originally implemented to allow backups from replicas/standby. In a future change we will make it so that backups to cloud repos are done via a temporary repo host, rather than on the pg instance (backups to local volumes will continue to be done on the dedicated repo host).

Other Information: