Implement full workout

[a-mabe]

Full workout includes Get ready, warm-up, work/rest, break between iterations, and cooldown.

New Features

• Added the ability to configure the "Get Ready" time before the workout starts.
• Added the option to set the duration of warm-up (before the work/rest intervals) and cool-down (at the end of the full workout) periods.
• Implemented a feature to repeat the timer a specified number of times, with optional breaks in between each set.

Improvements

• Improved the UI of the set work and rest seconds screen.
• You can now set the work and rest time to 0 seconds if desired.

New UI

Example of a possible workout:

Closes #94