Fix lwgeom_clip_by_rect

[dbaston]

The lwgeom_clip_by_rect function was introduced in 2.4 to:

Clip a geometry by a 2D box in a fast but possibly dirty way. The output geometry is not guaranteed to be valid (self-intersections for a polygon may be introduced). Topologically invalid input geometries do not result in exceptions being thrown.

In trunk, this function has been redefined to delegate to lwgeom_intersection and is no longer consistent with the description above. This was done because of a reported ​bug in GEOS, but that bug report cannot be reproduced. If the GEOS bug report is invalid, then lwgeom_clip_by_rect should be reverted to its 2.4 state.

Related: #4039, #4134

[strk]

Delegating clip-by-rect to lwgeom_intersection defeats its purpose, which was speed & tolerance to invalid input/output

[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