Expose function to report azimuth of edges from node

[strk]

Maybe it could be an extension of GetNodeEdges as that function already computes those azimuths.

Exposing them at the SQL level would simplify the research for face spikes which are hard to see with graphical tools

[strk]

Or the function could return angle from CW (or CCW) edge end, which may be easier to deal with (small angle == spike)