Add World Mercator WGS84 Quad tile matrix set

[navispatial]

Enhancing further implementations of #57 and #114.

"Web Mercator Quad" or "Spherical Mercator" or "Pseudo-Mercator" was already implemented in #57. It's most commonly used projection and tile matrix set in web maps, but based on spherical calculations, not ellipsoidal....

So the Open Geospatial Consortium has defined "World Mercator WGS84 Quad" that is the same as "Web Mercator Quad" but based on ellipsoidal calculations.

OGC Two Dimensional Tile Matrix Set:

• This Tile Matrix Set looks similar to the previous one (Web Mercator Quad) but this one is based on an ellipsoidal Mercator. Please note that the most northern latitude cover by this one is 85.08405903 (different from Web Mercator).
• The NGA Geomatics Office reminds the community to use DoD approved World Geodetic System 1984 (WGS 84) applications for all mission critical activities and encourages the use of WGS84 based tile matrix sets like this one and discourages the use of Web Mercator tiles based on Web Mercator such as WebMercatorQuad.
• The NGA Geomatics Office recommends the use of Universal zoom-levels scale set that are defined as true pixel size at ±31.0606963703645 degrees of latitude that implies a scale reduction at the equator of 0.857385503731176. This standard recommends the use of scale denominators at the equator for convenience.

[navispatial]

Currently geobase supports "WebMercatorQuad" and " GlobalGeodeticQuad / World CRS 84" that are most widely use. The geobase package is "base" tool, not aimed to implement tile matrices for all applications.

So closing this - let's see if needs are later identified for "World Mercator WGS84 Quad" and then reconsider again.

[navispatial]

Not actually "completed" but "rejected" until further notice...