EKF2: EV vel/pos only use EV q if enabled and valid

[dagar]

[dagar]

I'm now questioning if we should have a separate bit (EKF2_EV_CTRL) for using the provided EV q (_ev_q_error_filt) rather than including that under ev_yaw.

[DronecodeBot]

This pull request has been mentioned on Discussion Forum for PX4, Pixhawk, QGroundControl, MAVSDK, MAVLink. There might be relevant details there:

https://discuss.px4.io/t/px4-sync-q-a-may-15-2024/38773/1

[tedzaremba]

Big improvement - enables us to send external vision x, y, z data without quaternion or velocity.

Setup: HolyBro x500 v2 Bitcraze Bolt Arkflow Modalai FC-V2

Flight Test: https://review.px4.io/plot_app?log=13139bd1-177c-47cf-9c75-e3010983ee72