Fix filter label tooltip HTML rendering

What does this MR do?

Tooltips on labels used in a filter are now rendered as HTML

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

Shouldn't be

Why was this MR needed?

Fix existing bug (See screenshot below for reference)

What are the relevant issue numbers?

Closes #20592 (closed)

Screenshots (if relevant)

Before:

After:

Does this MR meet the acceptance criteria?

• CHANGELOG entry added
• Tests
  • 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