Add virtual cameras to support multiple simultaneous pipelines on the same camera

[jsimpso81]

Is your feature request related to a problem? Please describe.
No

Describe the solution you'd like
Add "virtual" camera, or some other mechanism that would allow multiple pipelines to execute simultaneously on a single camera. For example, April Tag detection and object detection simultaneously using the same camera.

Describe alternatives you've considered
Unless we have missed something the only way to do this now is to add a new physical camera.

Additional context
None.

[mcm001]

We've discussed multiple pipelines per camera before, and our conclusion was that since the needs of an apriltag camera vs a object detection one are pretty orthogonal anyways, and doing this breaks a lot of the current organization/piping of the backend, it wasn't worth supporting. That said, fork it and prove us wrong!