This is a larger patch that reworks the LCID handling throughout the
code.
- It first moves the RB/LCID mapping out of common.h into the RRC object
because different RATs may have different mappings.
- It adds a interface to RRC that other objects like RLC/PDCP/etc. may
use to get the bearer name of a specific LCID.
- The patch also introduces a PDCP config class.
- this patch moves common code shared between multiple UE types, i.e.,
UEs for different RATs into a commong base class
- it also introduces a switch during UE startup to instantiate the
selected UE type
- this patch changes the UL harq config to a dedicated one
instead of passing the whole MAC config which may be specific to
a specific RAT
- it also extends the RRC to fill the harq specific config field in the
MAC config
- clean up dl_harq and remove unused mac config