AI Tags: Respect the setting allowing/disallowing users to create tags

Currently AI Tags will suggest tags from the exisiting list of tags but also tags that don't exist. It will still suggest new tags if users don't have the right to create new tags.

I see this as a loophole for users to still select the suggested tags and thus create new tags though they are not allowed to do so.

Therefore the AI Tags should not suggest new tags if users do not have the permission to create new tags.