Generate global base grid

[veenstrajelmer]

Is your feature request related to a problem? Please describe.
Implement the generation of global grid. In interacter, this works like this:

• operations >> generate uniform curvilinear grid
• maze type 6 (globalnet)
• NR OF MAZES X: 192 (results in ~200km resolution)
• NR OF MAZES Y: has no effect, as the aspect ratio routine decides this.

This creates a global spherical grid [-180,180, -90,90] merged at the poles and connected at 180/-180. The pole should at least contain 8 cells, otherwise the model run will fail.

[veenstrajelmer]

This was implemented in meshkernelpy (unknown PR), but not completely according to expectations. This will be picked up as part of the follow-up issue: #181