[Flameshot] Add function to disable close on double click for pinned screenshots

### Feature Description Sometimes we need to temporarily pin a screenshot for quick reference or for screenshot composition. While using it, sometimes by mistake we might double click on the pinned window and it then disappears. It would be an improvement if this "close window on double click" would be configurable. An alternative would be to have a list of previously pinned (or even all recent) captures and reopen them, but this seems to be a lot more work than adding a bool to the config. Albeit we could save to a file, then later reopen it, we also would have to delete those temporary files.