feat: better snip + loop controls

[cdrani]

PR improves upon current snip controls:

1. More precise slider controls (update to 0.01 step for settings milliseconds of snip)
2. Update currentTime value after ~250ms after slider has not been updated. 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

---

closes #192, closes #193