Multiple Bimorph Mirrors without Identification

As a programmer I would like to know which bimorph mirror dodal class is appropriate for the physical bimorph mirror in a given beamline.

There are currently multiple in dodal: the `dodal.devices.bimorph_mirror.BimorphMirror` (for CAENels mirors) and `dodal.devices.focusing_mirror.FocusingMirrorWithPiezo`.

These are for different makes of bimorph mirror, but this is unclear from the code.

## Acceptance Criteria
- The bimorph mirror classes are clearly identified to bimorph mirror device they represent