aoft: expand cycles/families in mutations to the visible selection

[oliver-sanders]

See cylc/cylc-flow#4238 (review)

Tui: sibling cylc/cylc-flow#4246

Task pool commands (e.g. cylc hold) can only apply pattern matching to the n=0 window. This means that cylc hold <family>.<cycle> or cylc hold '*.<cycle>' don't work if <cycle> is not in the n=0 window.

The practical upshot of this is if you try to hold a family or cycle of tasks that are in the n>0 window, then nothing happens.

To get around this problem we should expand the cycle/family to the full list of tasks visible in the UI.

[oliver-sanders]

Adding the bug label as this will cause confusion for users.

This may require a little thought, we don't currently have the ability to expand a family/cycle to its constituent tasks so I think this is closely related to #434.

There is also the problem of knowing when to treat a cycle point as a cycle point and when to expand it to a list of IDs. It may be easier to attempt this after cylc/cylc-flow#4238.