ST_Subdivide slope precision and lost boxes

[komzpa]

ST_Subdivide loses parts of geometries and unnecessarily loses precision on polygon slopes.

Fix: ​https://github.com/postgis/postgis/pull/202

[komzpa]

In 16451:

ST_Subdivide: improved handling of polygons with many holes.

Closes #4038
Closes ​https://github.com/postgis/postgis/pull/202

[dbaston]

In 16676:

Make lwgeom_subdivide use lwgeom_intersection for clipping

lwgeom_clip_by_rect describes itself as clipping in a "fast but possibly
dirty way." This is not a good fit for lwgeom_subdivide, a primary use of
which is the optimization of point-in-polygon processes. That application
requires that the area covered by the subdivided geometry be the same as
the area covered by the original geometry, which in turn requires that a
robust intersection routine be used.

References #4038
Closes ​https://github.com/postgis/postgis/pull/281

[dbaston]

In 16679:

Revert lwgeom_clip_by_rect to use GEOSClipByRect

This commit reverts lwgeom_clip_by_rect to its implementation in PostGIS 2.2 -
2.4.

It makes trivial modifications to the MVT tests to reflect the different results
returned by GEOSClipByRect instead of GEOSIntersection. The changed results are
topologically equivalent to the previous results, and their orientation is
unchanged.

No tests have been commented out or made version-dependent.

Closes #4134
Closes #4135
References #4038
Closes ​https://github.com/postgis/postgis/pull/282