Remove check for zoom levels in ZoomController

[DominicOram]

In the ZoomController we currently raise a ZoomLevelNotFoundError if the zoom levels set by the user do not match the levels specified on the device. These could be different as we use a string signal but the device actually has an enum. The only purpose of this check is to give a nice exception to the user that lists the possible values that the zoom controller has. However, this behavior should probably be in ophyd-async (if it's not already).

Acceptance Criteria

• Test what ophyd-async does if you try and set an enum with in invalid string
• If ophyd-async responds with an error containing the actually valid strings then remove this check in dodal
• If not add this behavior to ophyd-async