Fixed pitch scale to align with pitch attitudes. The artwork was
incorrectly dimensioned, which meant that the distance between the 10 degree
and the 20 degree lines was different.

In addition to fixing the distances, the pitch scale is now fixed to scale
correctly with changing PFD size.
Added pitch desired indicator to PFD.
Cleaned up angle wrapping in QML PFD.
Renamed wrap_angles_XYZ to circular_modulus_XYZ in order to be consistent
with the flight code implementation.