[Epic] Add an ability to disable or re-enable a catalog

[LalatenduMohanty]

Here are some use cases for the same:

• As an admin, I don’t want to remove a ClusterCatalog resource from the cluster, but would like it to no longer perform over-the-air updates, serve the contents of the catalog, or be able to be used to install a package from the catalog via ClusterExtension resources.
• Scenario: catalog is unusable for whatever reason. Options currently available aren’t great – update all cluster extensions to use a new catalog to unblock cluster extensions, or, delete the problem catalog, this seems burdensome and problematic.
• As an admin, I want to apply my own catalogs and I do not want the default catalogs available on the cluster, but deleting the catalog might result in forgetting its contents, or remembering to reinstall the catalog.
  • Scenario: Solely using a custom catalog is desired, but I want to, someday, easily, revive the default catalog.

Sub tasks:

• RFC for adding an optional field to mark a ClusterCatalog either enabled or disabled  #1328
• Catalogd code implemention for "Optional field to mark a ClusterCatalog as Enabled/Disabled "  #1371
• operator-controller side code implemention for "Optional field to mark a ClusterCatalog as Enabled/Disabled " #1372
• Add documentation around how to enable or disable a catalog. #1388