[WebXR] Add generic VR controllers support #4376
Description
Currently, A-Frame supports only a certain set of VR controllers. However, if the controller is not known to A-Frame, the generic one should be used (see https://github.com/immersive-web/webxr-input-profiles/tree/master/packages/assets/profiles/generic).
In this case virtually ALL possible controllers will be supported.
- A-Frame Version: master
- Platform / Device: all