Video reader remains slow for large videos

[C-Achard]

Context

Our current VideoReader implementation is not optimal, and improvements to either the current code or using potentially faster readers such as decord2 may be helpful.

See:

• Increasing the smoothness of the video progress bar #89
• napari-dlc can not handle 200k+ frames videos during manual frame extraction #107
• Manual frame extraction is very slow (version 3.0.0rc14) DeepLabCut#3264:

I just tested. napari-deeplabcut 0.3.0.0 is still slow, though better than the old version. There is still a noticeable delay (~10 seconds) between dragging the video progress bar and displaying the new frame.

My RAM, CPU, and GPU should be very powerful (64 GB DDR5 + Intel Core i7-14700 KF + RTX 4080 16GB).

Originally posted by @ChaoqunYinNeuroscience in #3264