[Feature request] Simplify keyboard shortcut combo components

### Description

The current keyboard shortcut combo components are over-engineered and could benefit from a rebuild. This covers two related improvements:

- **Rebuild the keyboard shortcut combos** in a simpler, more maintainable way.
- **Replace instance-swap properties** for keyboard shortcut components with nested instance drop-downs, which are easier to use in Figma.

### Why

The current implementation has more complexity than needed, making the components harder to maintain and harder for users to configure.