CLI: Minor additions #12795

[Erovia]

Description

Make the output a little bit easier to read and provide more context to the user when the selected keyboard name is already used.

Types of Changes

• Core
• Bugfix
• New feature
• Enhancement/optimization
• Keyboard (addition or update)
• Keymap/layout/userspace (addition or update)
• Documentation

Issues Fixed or Closed by This PR

Checklist

• My code follows the code style of this project: C, Python
• I have read the PR Checklist document and have made the appropriate changes.
• My change requires a change to the documentation.
• I have updated the documentation accordingly.
• I have read the CONTRIBUTING document.
• I have added tests to cover my changes.
• I have tested the changes and verified that they work and don't break anything (as well as I can manage).

[tzarc]

Deferred to next cycle as it's not a bugfix.... unless we decide we want to push it through?

[Erovia]

Up to you.
These are just the suggestions I wanted to leave on #12795. :)

[peepeetee]

Might I suggest having the

provide more context to the user when the selected keyboard name is already used

part of this PR to be merged as a bugfix?

Technically it is a bug, since there should be an error message displayed rather than nothing at all
And it would have helped immensely with my keyboard addition troubleshooting process if said part was included in current develop