grps: Add test for NS messages that shall be ignored

Several messages shall not be answered when a RESET hasn't been
received on a NS-VC:
- NS_RESET_ACK (see 3GPP TS 08.16, 7.3.1)
- NS_ALIVE_ACK (see 3GPP TS 08.16, 7.4.1)
- NS_STATUS (see 3GPP TS 08.16, 7.5.1)

Sponsored-by: On-Waves ehf
2 files changed