Implement "New circuit for this site" on Android

I realized we have an issue about the circuit display, but not an issue about getting a new circuit for a certain site.

I think it'd be easy to start with this feature, even without providing the full circuit display (e.g., on desktop we have a new circuit button in the hamburger menu, I think we could do the same on Android).

The circuit display data is already implemented in mobile/shared/modules/geckoview/GeckoViewContent.sys.mjs, something similar for the new circuit should be very easy to do.

Calling it from the Java/Kotlin side is the difficulty from my perspective 😄. We need to add it where we have access to the engineSession (unless this changed between 115 and 128).

Design prototype on Figma