[Feature request] Hold take photo button for quick recording

[Terkyz]

Describe the solution you'd like.
When I am in photo mode and I hold my finger down on the take picture button, instead of the "Take picture" pop-up appearing, a recording is started.

**Additional context
This is a function that has the Whatsapp camera that I personally like because it is very useful and helps to save time, it would be great to have it in Libre Camera.