blueapi-ui: Make sure all plans render well

A number of improvements would make the plan page more usable:

- [x] Should be alphabetised (as a minimum), and allow users to "favourite" plans. "Favourite" plans should be shown at the top the list.
- [ ] Some plans currently don't render well (`move`, `move_relative`, `set_absolute`, `set_relative`, `list...scan`, `num...scan`, `step...scan`, ...)
- [x] List of plans should scroll independently of the plan UI

Start at the blueapi-ui plan page and inspect how the named plans—move, move_relative, set_absolute, set_relative, list...scan, num...scan, step...scan—are rendered. Compare their output with plans that already render correctly; done means each listed plan displays well in the plan UI.

Written by the indexing model from the issue text.