AP_ExternalAHRS: added ANU CINS state estimator #34221

Job	Run time
build (chibios, Durandal)	11m 56s
build (chibios, MatekF405)	23m 6s
build (chibios, KakuteF7)	21m 8s
build (chibios, MatekH743-bdshot)	11m 47s
build (chibios, Pixhawk1-1M)	10m 45s
build (chibios, MatekF405-CAN)	4m 40s
build (chibios, DrotekP3Pro)	3m 58s
build (chibios, Hitec-Airspeed)	4m 14s
build (chibios, f103-GPS)	6m 6s
build (disco, armhf)	8m 16s
	1h 45m 56s

Provide feedback