Add an option to do Precise Seek

[rezgi]

Is your feature request related to a problem? Please describe (REQUIRED):
Allow the ability to do precise seeking. This option could go well in conjunction with the feature request to get the ongoing decoded frame and time. This way we could very precisely swap from one video to another at the exact same play head.

Describe the solution you'd like (REQUIRED):
Enable the bool argument for precise seek (seek_exact) in pl_mpeg.h#L466

Describe alternatives you've considered (REQUIRED):
mpeg.decode() takes delta time for now and I'm trying to divide it in order to get 24fps and match the video play rate.