Transceiver: Move out TRXD socket send code to prepare for TRXDv1

Only old v0 is supported so far. TRXD protocol related data/logic is
moved to its own file out of Transceiver class. Code is refactored so it
can be re-used later by TRXDv1.

Related: OS#4006
Change-Id: I5786dd44b076202c6f1a6e82405670e8605797ed
5 files changed