IVGCVSW-3964 Implement the Periodic Counter Selection command handler

IVGCVSW-3964 Implement the Periodic Counter Selection command handler

 * Improved the PeriodicCounterPacket class to handle errors properly
 * Improved the PeriodicCounterSelectionCommandHandler to handle
   invalid counter UIDs in the selection packet
 * Added the Periodic Counter Selection command handler to the
   ProfilingService class
 * Code refactoring and added comments
 * Added WaitForPacketSent method to the SendCounterPacket class
   to allow waiting for the packets to be sent (useful in the
   unit tests)
 * Added unit tests and updated the old ones accordingly
 * Fixed threading issues with a number of unit tests

Signed-off-by: Matteo Martincigh <matteo.martincigh@arm.com>
Change-Id: I271b7b0bfa801d88fe1725b934d24e30cd839ed7