Feature: Better Snip + Speed Controls

[cdrani]

Improvements

1. More precise slider controls (update to 0.01 step for settings milliseconds of snip)
2. Update currentTime and playbackRate values on slider thumb leave. Instantaneous for manual inputs.
3. New manual inputs for setting start and end times (again - up to milliseconds of snip). Follows HH:MM:SS:MS notation.
4. Separate looping logic and icon from Spotify's repeat-1
5. Add loop icon to popup ui
6. Add loop option to shortcut keys command

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Feel free to leave some thoughts and/or issues/bugs in this discussion related to these changes.