Draft: Implement GetFaceMaximalOuterRing function
The idea of this function was for it to be faster than ST_ExteriorRing(ST_GetFaceGeometry(...))
but up to this point the code is actually slower, so doesn't make sense to merge as-is.
The only case in which this code is faster is when the subject face has a lot of holes, but we can't tell in advance so there's no way for us to decide whether to go with one or the other implementation.
Edited by Sandro Santilli