Support RRC idle for NR SA

Allow timers between NR_ADVANCED and NR_CONNECTED_RRC_IDLE separate from
NR_ADVANCED to NR_CONNECTED.
Make NrIdle state backwards compatible with NrConnected state.
Support primary cell change during RRC idle

Test: atest NetworkTypeControllerTest
Bug: 298233308
Change-Id: Ic19f6f0985b267312c7003fcddc627548ffa41f8