Make Movable also a Readable and add a separate Protocol that can set but not read

[noemifrisina]

Current Behavior

The Movable protocol is used to describe motors, which in 99% of the use cases also need a read method.

Possible Solution

• Have Movable inherit from Readable and use this in the plans/plan_stubs
• Make a new Settable protocol which has set but not read
• Use Settable in the RunEngine code

Context

Adding type hints in #1712 highlighted the fact that the definition of Movable does not include a read method, which is required by some plans which may be used on motors, eg. bps.trigger_and_read as used in bps.one_1d_step

Small side note: in #1712 code showing this behaviour has been temporarily marked with #type: ignore to get the CI tests to pass.