Extract nr_ra_procedures.c into a separate library and add a testcase for init_RA function.

The testcase redefines the following functions as stubs:
 - nr_mac_rrc_ra_ind
 - nr_write_ce_ulsch_pdu
 - mac_rlc_data_req
 - *lockGet_ul_config
 - release_ul_config
 - remove_ul_config_last_item
 - nr_ue_configure_pucch

These stubs can be used to check init_RA behavior