"Instant mode" toggle in main window

[richiemcilroy]

Toggling this mode will make the next recording upload on the fly whilst recording (Loom style functionality).

It won't record the camera separately, it will be included in the same file (so we can upload on the fly). Camera will be captured by including it in the view of screen (so camera window shouldn't be excluded from screen recording).

Ideally, we will still somehow upload the in progress .mp4 on the fly so we don't have to deal with HLS again…