[fix] Add checks to estimated resolution angle

• Context : The azimuthal angle is estimated with the first scan, it is used to invalidate points on occluded areas boundary.

• Goal : Avoid using not plausible angle estimations

• Actions :

  • Add checks to use the estimated azimuthal angle (if the first scan is not well structured)
  • Use a default azimuthal angle if it could not be estimated robustly (Velodyne 10Hz) and print a warning.

@nicolas.cadart PTAL