Review the subarray observation control state machine(s)

Why now?: Following decisions and changes resulting from --ADR-3-- and ADR-4, and discoveries of some current design choices that reveal potential inconsistencies, the subarray obsState state machine that is described in SKA-TEL-SKO-0000860, and revised as part of --ADR-3-- needs reviewing, and probably some changes. This state machine is a core and common part of the whole OMC system and it is important to get the architecture right to support key use cases.

Scope: TMC (OSO?). SDP, CSP.Mid, CSP.Low

Qualities: Modifiability, Maintainability

Some issues to consider:

1. The possibility of adding a new transitional state to obsState, indicating that a system is "Assigning" resources.
2. The future of the EndSB command in the subarray state diagram. This should also include looking at the use of "Reset" and "GotoIdle"
3. How do we efficiently run two instances of the same SB definition in series, preferably without re-assigning resources?
4. What should "ReleaseResources" mean for each system, including the issue of partial resource release (and assignment),

In doing this it is worth examing the overall design again, including the learnings from -ADR-3- and ADR-4 and their implementation.