Feature Request - Identify speakers based on left/right stereo channels

[snex]

Let's say you have a video with 2 individuals speaking, one on the left and one on the right. It would be nice if the subtitle output could identify who is speaking based on user input and which audio channel the voice is coming from.

Example command: auto_subtitle --left_speaker ALICE --right_speaker BOB input.mp4

Then the output SRT looks like:

1
   00:00:00,000 --> 00:00:15,160
   ALICE: Hi Bob, how are you today? BOB: Hi Alice, I'm great!