Add camera torch and zoom

[tomm1e]

Handles screen events by video source. I put the input event logic for camera in a new folder (src/im) to keep things organized. New video sources can add event logic there.

New shortcuts:

• MOD+q: Camera toggle torch
• MOD+1: Camera zoom in
• MOD+2: Camera zoom out

New CLI options:

• --camera-torch (Turn on torch when starting)
• --camera-zoom-step=0.05 (Adjust step value)

Tested on Samsung Galaxy A52 5G, no issues.

Closes #4670, #4903

Note: I think some functions such as apply_orientation_transform could be put into a util file since those could be used across all video source event handlers.

[rom1v]

Thank you 👍 Looks great.

However, to be honest, it might take some time (at least weeks) before I can review properly and merge.

FYI, in the past, I had started a branch (torch, which I just pushed), but I stopped before adding the mechanism for camera controls.