ekf2: update EV height state machine (small piece of EV overhaul)

- respect new EKF2_EV_CTRL parameter for VPOS usage
  - EV hgt rotate EV position before usage (there's often a small offset in frames)
  - EV hgt reset use proper EV velocity body frame
  - try to keep EV hgt and EV vel state machines consistent
  - small incremental piece of https://github.com/PX4/PX4-Autopilot/pull/19128

src/modules/ekf2/test/sensor_simulator/ekf_wrapper.cpp

@@ -77,7 +77,7 @@ void EkfWrapper::setExternalVisionHeightRef()
 
 void EkfWrapper::enableExternalVisionHeightFusion()
 {
-	setExternalVisionHeightRef(); // TODO: replace by EV control parameter
+	_ekf_params->ev_ctrl |= static_cast<int32_t>(EvCtrl::VPOS);
 }
 
 bool EkfWrapper::isIntendingExternalVisionHeightFusion() const