after adding the thread-safe PCAP writer functionality to the EUTRA
MAC object it became clear that we don't wont to replicate the
same for the NR object.
This patch therefore refactors the class that now supports both EUTRA and
NR rats. The old mac_nr_pcap.[h/cc] has been deleted. All test-cases
and usages now use the new object that needs to pass the RAT type in
the ctor.
this patch addresses the last open point of #2160