Rotation of camera and beamsplitter when the Microscope submodule is brought forward to v7.0.0-beta4

In !20 (merged) the Microscope submodule is brought forward to openflexure-microscope at the v7.0.0-beta4 release. This has a refactored optics module code that has no delta_stage variable to adjust the camera and beamsplitter rotations.

For the delta_stage modules the optics_config variables are "beamsplitter_rotation" = -60 and "camera_rotation" = -45 (from statments in the Microscope v6.1.5 code)