CK5 code block languages are not configurable

Here's a patch that makes this configurable.

Fixed CCF on #2

forgot to add a file in patch #3 please ignore it. uploading a new patch.

This is a duplicate of ✨ Ability to configure additional languages (e.g. "bash" or "SQL") for CKEditor 5 CodeBlock plugin Fixed . That patch is much further along. Please review that instead, @lauriii, @merchel and @TanujJain-TJ!