[Enhancements] Screen Lock in Hekate

I think that it would be a good idea to add a Screen lock function similar to the touch based TWRP Android Recovery mode to Nyx/Hekate.

Example of the Screen Lock Function in TWRP

The screen lock feature isn't for security, it just ensures that buttons don't get randomly pressed if it's in a Pocket/Bag.

Edit: I changed this issue to reflect that this is about Lock screen, sleep mode is something separate entirely.