LEAP Logging infrastructure

[KasraF]

We need to implement logging for LEAP for use with the user study. From our meeting on 03/10/2023, I have the following events to log:

1. Time of Leap panel opening
2. Time they press Ctrl+Enter to close it/say they're done. (and which completion is currently selected?)
3. When they click Preview (and which one)
4. When they edit (we get this from RTVDisplay)
5. Log when panel hides away
6. Log when panel comes back in focus

[KasraF]

See first draft of this in cf9a212. I will keep this open for now, since we need to test it and make sure everything is working as intended..