feat: detect unused components to help clean up old code

[acidjazz]

🆒 Your use case

Have a CTA or auto-run something that shows all found components that are not used

🆕 The solution you'd like

A list of all components not found to be used

🔍 Alternatives you've considered

No response

ℹ️ Additional info

Be very cool to make sure stale code can be removed from the project

[acidjazz]

I imagine <component :is might make this tricky, maybe list where those are as well as a warning

[manniL]

Closing in favor of #358