Multi-rotation and multipin plans don't support certain combinations that are implied by the parameter model

[rtuck99]

Currently the plans only support a fixed number of frames per rotation, whereas the MultiRotationScan RotationScanPerSweep allows variable rotation width which implies variable frames if you have fixed exposure per frame. Also there's a fixed omega_start in the DetectorParams which we currently assume to be the same as the first.

We should limit the flexibility allowed by the model if we decide not to implement this functionality, or at least validate that these constraints are maintained.