add option to refine to min-distance in meter instead of degrees in meshkernel.MeshRefinementParameters() (in case of a spherical grid)

[veenstrajelmer]

Is your feature request related to a problem? Please describe.
When refining, one can provide a min_face_size argument. In case of a spherical grid, this is in degrees. Mostly, we want to generate grids that adhere to a minimal size in meters (also when spanning over a long latitude-distance).

Describe the solution you'd like
It would be convenient if it can be supplied in meters, like the hmin argument in the dflowfm kernel.

[veenstrajelmer]

This is already implemented when using is_geographic=True