Update ATMCS interface according to discussion with Patrick, Rolando and Russell
- Add M3 motor encoder data to existing telemetry topics.
- Remove ATMountState enumeration values that overlap summary state.
- Remove M3State enumeration values that overlap summary state.
- Reorder fields in the mountEncoders telemetry topic to the standard order used everywhere else.
- Rename command topic fields that are ignored to ignored.
- Rename brake fields from engage to engaged.
- Remove m3RotatorDetentLimitSwitch to m3RotatorDetentSwitches and remove Detent from the field names.
- Remove redundant State suffix from ATMountState_ and M3State_ events, e.g. change M3State_DisabledState to M3State_Disabled.
- Add documentation for all topics (and fix existing incorrect documentation).