A future CL will allow users to specify search paths in their settings.
PiperOrigin-RevId: 846240293
Change-Id: I1a1a4027d0fc85004a12fe01a406f50fd929f3e4
Inlines the platform::LoadMujocoModel into the App class which simplifies
the logic and allows us to correctly display loading errors.
Also updates shortcuts:
Load Model (Ctrl+L) -> Open File (Ctrl+O)
Reload Model (Ctrl+R) -> Reload Model (Ctrl+L)
PiperOrigin-RevId: 840232553
Change-Id: I957d29046ae681d2aeb69310c3a2eec64d042d49