TMC to Dish interface (re-)work.

A number of observations were made on the TMC-Dish interface during the Mid-ITF workshop, and independent testing by the TMC, Maple, Atlas teams.  Few of the observations were:

1.Lack of Abort command on the Dish LMC (The Dish only provides AbortCommands from the SKA tango base Class, which only clears the queue )

2. Optimizing the track table updates provided by the TMC 

3. Handling of dish pointing state (= slew, ready, track) in TMC, considering that the pointing state could change during a scan. [e.g. SKB-468].

4. Considering the dish failures/ redundancy when arriving at the subarray observation state 

The scope involves analysis of the observations, making design changes in discussion with the related stakeholders and implementing the improvements on the TMC. (A separate feature may be required for the changes on the Dish, if any).