CSP_Mid.CBF Subarray - implement commands Abort and Restart (SS-27)

The obsState state machine for a subarray includes an Abort command that can be accepted in some obsStates. It should be possible to send an Abort command to the Subarray controller, and have the current activity stop, and all devices move to the ABORTED state. As much as possible the subarray and the child devices should retain existing configurations, allowing examination of the current system state.

From the ABORTED state it should then be possible to issue the Restart command to set all child devices to a known obsState, the EMPTY obsState, in which the subarray device has no resources assigned. See the Decision in ----ADR-8----.

https://confluence.skatelescope.org/pages/viewpage.action?pageId=105416556

The ticket  SP-754 describes implementation on the TMC side, and the ticket SP-1100 describes implementation on CSP.LMC side. 

Mid.CBF Sub-array implements :

• command abort() 
• command restart()
• command reset() 

and performs state transitions as described in --ADR-8--

https://confluence.skatelescope.org/pages/viewpage.action?pageId=105416556

The state transitions may be adjusted  to Mid.CBF design - detailed analysis will be performed and behaviour described before the implementation begins.

State transitions are propagated to devices used by the sub-array as applicable (to be analysed and described in detail before implementation begins).