Motors: Easier way to set motor descriptions

# Feature Description

As someone working with motors on a beamline it woule be helpful to edit motor descriptions to match what the motor is connected to for reading on the motor table

## Explanation
Every motor has a default description, and you will see that on the motor table in the GUI if it hasn't been changed. That isn't overly descriptive, and whilst many have been created during the migration, or when systems are installed, this involves a write to the `.desc` field of the motor record for that motor. Whilst this isn't difficult, being able to make the change more easily in the GUI would be helpful for ease of use, especially when setup is undertaken by others.

### Additional Information
As this is a change, and those descriptions are often fixed, making it not too easy/prominent is probably ideal. Consider ways to limit the chance for accidentally changing the description of the motor.

# Acceptance Criteria
- [ ] There is a box available either on or via the Motor Details OPI that allows you to set the description.

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