WIP: Issue templates UI

What does this MR do?

Implements the issue templates UI from #18656 (closed).

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

What is the best way to merge this with !4981 (merged) so I can continue?

Why was this MR needed?

~"feature proposal"

What are the relevant issue numbers?

Related to #18656 (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