Discovered while testing MDLQA-19373

After disabling Generate text and Generate image both 'AI generate text' and 'AI generate image' options are displayed on the 'Generate AI content' menu and also under Insert, see following images:

IMPORTANT: I was able to generate the text with that setting disabled, maybe we should have some restriction in the backend to prevent the request is not processed as well, not just hiding the options on Tiny.