Improve UX of entering autocomplete predictions

[maxpatiiuk]

If you have a lot of Autocomplete Predictions, like I do, editing them becomes cumbersome in the current UI.

Possible improvements:

• make the height of that tool lower than the screen height

  • otherwise, you have a giant scroll bar inside of a giant scroll bar

• I mistakingly clicked on a wrong edit button in here:
  

  • one button saves autocomplete predictions, another one would cause you to loose unsaved changes
  • may be improved once autocomplete predictions container is less tall, thus it's clearer which Edit button relates to what
  • still might want to add some sort of unsaved-changes detection (also when closing Calendar Plus)

• consider moving autocomplete predictions editing into a separate dialog - would save space in the dashboard (and it doesn't need to be visible most of the time), and when doing editing, would give more space, and better UX

  • or if not dialog, then separate tab/page

Also, consider renaming "Autocomplete predictions" to "Categories" to be less geeky and to not constrain the feature's future use cases (#238)