Let ST_LocateBetweenElevations work for polygons and triangles

[komzpa]

Right now I have to work around:

ST_ConvexHull(ST_LocateBetweenElevations(ST_Boundary(geom),(minute - 1) * 60, minute * 60))

This could be a direct LocateBetweenElevations call.

[komzpa]

In 16949:

ST_LocateBetween[Elevations]: Support GEOMETRYCOLLECTION

References #4155

[komzpa]

In 16952:

ST_LocateBetween[Elevations]: support POLYGON

Output may be invalid for non-convex, area is preserved.

References #4155
Closes ​https://github.com/postgis/postgis/pull/319

[komzpa]

In 16954:

ST_LocateBetween[Elevations]: support TIN and TRIANGLE clipping.

Triangle is converted into a TIN that has several triangles with same orientation.

Committed in Paris Airport.

Closes #4155