[Feature/Improvement] Add more sound options

[a-mabe]

Purpose: As a user, I would like to be able to choose what sound effects play during my workout.

More details: Provide more than just the default sound effects. Examples of more options:

• Soft sound effects mode. Sound effects played are less harsh than the default.
• Vocal mode. Play a voice that starts "Work" and "Rest".
• Class mode. Play longer sound effects for a group exercise class. This ensures the full group hears the audio cue.
• No audio mode.

Allow the user to either select these specific modes, or change each sound effect individually.

Acceptance Criteria:

• Additional sound effect options are provided and are configurable.

[a-mabe]

Closed by #51