Extract common CellGroupConfig encoding logic from
ue_context_setup_request() and ue_context_modification_request() into
encode_cellgroup_config().
Replace uper_encode_to_buffer() with uper_encode_to_new_buffer() to:
- Remove 1024-byte buffer size limit
- Automatically allocate correct buffer size
- Simplify code (no manual bit-to-byte conversion)
- Align with other protocol encoders
Guido Casati
0b8fb49a38