Bugzilla Integration

What does this MR do?

Adds Bugzilla as a project service for external issue tracking

Are there points in the code the reviewer needs to double check?

Why was this MR needed?

Provides a notable Bugzilla option for use as an external issue tracker. Existing Custom Issue tracker can be used to setup Bugzilla but this makes it clear that Bugzilla is an option.

What are the relevant issue numbers?

Closes #14669 (closed)

Screenshots (if relevant)

Does this MR meet the acceptance criteria?

• CHANGELOG entry added
• Documentation created/updated
• API support added
• Tests
  • Added for this feature/bug
  • All builds are passing
• Conform by the style guides
• Branch has no merge conflicts with master (if you do - rebase it please)
• Squashed related commits together