Allow selection gui to persist

I want to record part of my screen with wf-recorder. That is possible with slurp, however it's hard to perform actions within the selection if I don't have a constant indication of the recorded area, as slurp quits after selection.

example:

https://user-images.githubusercontent.com/74874782/159025893-d4768402-8466-4d8f-aa64-5f5ba5a8db63.mp4

Start with slurp's selection entry point and review how it exits after a region is chosen, using the linked recording as the behavioral reference. The work is done when the selected area remains visibly indicated while the user performs actions within it, without losing the intended region.

Written by the indexing model from the issue text.