* give the correct UE_id instead an index of the protobuf message (they can
diverge from each other)
* in the PDCP part of the RAN API, the RAN API has to make the conversion UE_id
(MAC) to UID (PDCP)
* a follow up commit could clean up the interfaces:
- the MAC functions take the UE_id
- the RRC functions take the RNTI
- the PDCP functions take the UID
this would mean the caller has to find those ID but would decrease
computations since the RAN API functions do not have to do that themselves
- setter & getter have been renamed
- setter sets scheduler name and links to the corresponding function
- it also returns whether it succeeded (whether the scheduler callback is
non-null)
- it performs a strdup on the scheduler name
- the remove function free the scheduler function name
- when changing values RC.rrc[i]->configuration should be changed too
- then, RRC_RECONFIGURATION_REQ will pass the changed conf down until PHY
- give warnings at functions that are not implemented
- rename functions
flexran_get_tdd_ack_nack_feedback() -> flexran_get_tdd_ack_nack_feedback_mode()
flexran_get_ue_pmi() -> flexran_get_ue_wpmi()