Changed parameter in unpack function to be inline with other unpack functions.
Changed nfapi_p7_allocate call to calloc to avoid dependency to NFAPI_LIB.

Added unitary test for RACH.indication( test pack/unpack, free, copy and compare )
Added constant NFAPI_NR_RACH_IND_MAX_PDU to follow constants related to other P7 messages limiting the maximum number of PDUs to use.

Removed now unneeded dependency to NFAPI_LIB and NFAPI_USER_LIB