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

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

* Receive and process the stream metadata from the client.
* Send the connection ack packet.
* Wait in a receiving thread and print the packets.
* GatordMockTest and Impl for PeriodicCounterCapture CommandHandler
* CaptureData class to retain packet data
* MockUtils
* Update SocketProfilingConnection to fix non blocking receipt of packets.
* Restructure directory layout following review comments.
* Extract the mock service into a static library in the cmake files.

Signed-off-by: Colm Donelan <Colm.Donelan@arm.com>
Signed-off-by: Keith Davis <keith.davis@arm.com>
Signed-off-by: Mike Kelly <mike.kelly@arm.com>
Signed-off-by: Finn Williams <Finn.Williams@arm.com>
Signed-off-by: Kevin May <kevin.may@arm.com>
Change-Id: I33c1c9f93976708c9315f71290d42cff53b8c075