Create unit test: Verify that the time-stamp parsing logic works for a variety of time-stamp formats

[utsab]

A youtube video description could have timestamps in a variety of formats:

• 01:34:21 chapter title
• 1:34:21 chapter title
• 34:21 chapter title
• 4:21 chapter title
• (4:21) chapter title
• [4:21] chapter title

We should have a test cases to confirm that each of these formats is properly handled.