IVGCVSW-3721 Add support for startup sequence (Mock Gatord service).

IVGCVSW-3721 Add support for startup sequence (Mock Gatord service).

* Updated ExecuteNetwork to propagate a configured Runtime down to RunTest.
* Fixed the creation of PeriodicCounterCaptureCommandHandler to match
  other handlers.
* Moved around some printouts to make the MockGatorD output more useful.
* Added details to the exception handling for problems in the
  GatordMockService receive thread.
* Mockutils::ConstructHeader is only used in GatordMockTests. Moved it
  in there and deleted MockUtils.hpp
* Refactored SendPeriodicCounterSelectionList to use ProfilingUtils.
* Added PeriodicCounterSelectionResponseHandler to received packet echoed back.

Signed-off-by: Colm Donelan <Colm.Donelan@arm.com>
Change-Id: I4accdbf6cf5dd3f7dcc12b210b8360b4a5e4e277