Check numpad enter for text input submissions

[Jarrio]

No description provided.

[jeremyfa]

Thanks for the PR, I'm not against that change, but the way it is done is not correct:

• As with LSHIFT/RSHIFT or similar, we should not abstract away what exact key have been pressed at backend level.

• If we are going for that change:

  • The backend should call a new method called ceramic.App.app.textInput.kpEnter() so that we can decide what to do with it at higher level and we don't lose any information on the way

  • All backends should be supported, not only clay backend. The call to kpEnter() should also be added in unity backend

[jeremyfa]

Changes look good now, thanks!