1. Removed SDAP struct from protocol context.
2. Added configuration for the SDAP.
3. SDAP doesn't use pdcp_entities, the values come from function arguements.
4. Make nr_pdcp_ue_manager accessible from SDAP.
5. Avoid using the PDCP locking mechanism in SDAP.
6. Removed nr_pdcp_find_entity_sdap function.
7. Rename dummy eNB function to make GTP compile (no SDAP).
8. Fix: Regression issues with LTE
9. Fix: Regression issues with NR CU/DU
athanassopoulos