feat(developer): Indicate Key Right Boundary Position in the Status Bar in Touch Layout Editor

### Is your feature request related to a problem? Please describe.

When adding padding to layout keys along a row, it can take a number of trials to get the keys of one row to align with another. It would be helpful if we could view the horizontal X coordinates of the key corners; only the right corner is really necessary.

### Describe the solution you'd like

When a key is selected in the Touch Layout view, display its right side X-coordinate in the status bar. This would be analogous to the "total" width value shown along the right side of a row.

Alternatively, perhaps a better idea, present the value in the left pane that has the key details.

### Describe alternatives you've considered

_No response_

### Related issues

_No response_

### Keyman apps

- [ ] Keyman for Android
- [ ] Keyman for iPhone and iPad
- [ ] Keyman for Linux
- [ ] Keyman for macOS
- [ ] Keyman for Windows
- [x] Keyman Developer
- [ ] KeymanWeb
- [ ] Other - give details at bottom of form

### Keyman version

18.0.238

### Operating system

Windows

### Device

Laptop

### Target application

N/A

### Browser

N/A

### Keyboard name

N/A

### Keyboard version

N/A

### Language name

N/A

### Additional context

_No response_