aotf: beautify forms

[oliver-sanders]

The auto generated forms used to edit mutations work alright but aren't the prettiest. In particular lists aren't the most intuitive and help could be integrated better.

• Make lists nicer.
• Ensure descriptions (field and type) are presented nicely as appropriate.
  • Note, a field may have a description, however the type of the field may also have a description.
  • For more info see Improve schema docs for broadcast mutation cylc-flow#4902 (comment).
• Improve the style (note we may move away from Vuetify which makes this challenging).

[oliver-sanders]

The broadcast form isn't the clearest at the moment, we could do with a custom component for BroadcastSetting that makes it clearer.

The docstring for BroadcastSetting should appear in the question-mark help box as for some other settings, however, doesn't. Should make sure that's done when attempting.

• Improve schema docs for broadcast mutation cylc-flow#4902 (comment)
• Improve schema docs for broadcast mutation cylc-flow#4902 (comment)