Import/export SNAP areas to allow custom generation and backup/restore

Allowing importing snap areas would allow programmers to create their own areas very easily, also allowing to create backups for those annoying times a monitor reconnection losing the snap areas.

My use case would be:

  1. configure a few snaps and export to use as template
  2. use a scripting tool (unrelated to BTT) programatically create all splits for each of my monitors and save it as a file
  3. import the snaps and never worry about them again.

It would also help people a bit OCD like me that like all snaps aligned and proportional.