Migrate popups in pocket settings menu to ImGui

[Brambor]

Summary

Interface "Migrate popups in pocket settings menu to ImGui"

Purpose of change

• Resolve uilist issues from migration #74341 #75661 (This only addresses the last problem or two standing).
• Fixes Pocket 'Set priority' input box was hidden #77290

Describe the solution

Migrate to Imgui.

Describe alternatives you've considered

Testing

Priority before (behind the window):

Priority after:

• Check values 12 and -5 work

Save preset before:

Save preset after:

This shadow is not there either anymore:

Additional context

[PatrikLundell]

I may misinterpret your description, but if this PR only addresses one of two issues (and the other one hasn't been fixed elsewhere already), it shouldn't use a code word that closes the issue, but rather one that isn't a code word (like contributes to, so the PR is still linked to by the bug report).

[Brambor]

• This PR is the last nail in the issue. Except for one additional misbehaviour, which I made issue PageUp, Home misbehave in pocket settings menu #78469 for right now.
• My thought process for the keyword was: "This will resolve the last problem, so I will close the issue once this PR is merged. Then I can just automate that with the keyword resolves."

That huge issue agglomerate has to end in favour of small issues. And there is nothing left there except for this PR and the issue I just made.