Videos, presenter mode and menu labels in the React portal

Three things the Blazor portal already did are now available in the React portal too. Videos on a page — lecture recordings, walkthroughs and embedded players — render and play instead of being skipped. Slide decks can be driven from the keyboard in presenter mode, using the usual arrow, space, page, Home/End and Escape keys to move between slides and leave the presentation.

Navigation menu items also show their titles and icons again, and clicking them works. Items that group other entries expand to reveal them. Previously a menu built by the mesh could come through with its labels missing, which made the navigation hard to use.