ekf2: improve preflight checks and publish status
ekf2: improve preflight checks and publish status

Separate the vertical and horizontal checks for use by local position validity reporting
Add checking of yaw using a decaying envelope filter to the horizontal checks.
Publish the check result to estimator_status topic.

krbeverx/Firmware,dagar/Firmware,acfloria/Firmware,krbeverx/Firmware,Aerotenna/Firmware,krbeverx/Firmware,acfloria/Firmware,mcgill-robotics/Firmware,Aerotenna/Firmware,dagar/Firmware,PX4/Firmware,jlecoeur/Firmware,mcgill-robotics/Firmware,acfloria/Firmware,Aerotenna/Firmware,jlecoeur/Firmware,PX4/Firmware,mje-nz/PX4-Firmware,PX4/Firmware,krbeverx/Firmware,krbeverx/Firmware,mcgill-robotics/Firmware,Aerotenna/Firmware,krbeverx/Firmware,jlecoeur/Firmware,dagar/Firmware,PX4/Firmware,Aerotenna/Firmware,mje-nz/PX4-Firmware,krbeverx/Firmware,PX4/Firmware,mje-nz/PX4-Firmware,jlecoeur/Firmware,dagar/Firmware,PX4/Firmware,mcgill-robotics/Firmware,mcgill-robotics/Firmware,mje-nz/PX4-Firmware,mje-nz/PX4-Firmware,mcgill-robotics/Firmware,acfloria/Firmware,acfloria/Firmware,mcgill-robotics/Firmware,jlecoeur/Firmware,acfloria/Firmware,PX4/Firmware,acfloria/Firmware,Aerotenna/Firmware,mje-nz/PX4-Firmware,jlecoeur/Firmware,jlecoeur/Firmware,Aerotenna/Firmware,mje-nz/PX4-Firmware,dagar/Firmware,dagar/Firmware,dagar/Firmware,jlecoeur/Firmware