Add support for multiple polygons in mesh2d_delete()

[veenstrajelmer]

Is your feature request related to a problem? Please describe.
Currently, deleting networks within a multiplolygon is possible via two ways:

• looping over each polygon, greating a meshkernel.GeometryList() to use in mk.mesh2d_delete()
• concatenating the polygons with -999 values (an arbitrary value), nans are not supported.

Describe the solution you'd like
It would be convenient if a list of meshkernel.GeometryList() could be supplied to mk.mesh2d_delete(). Maybe even better, if the hydrolib.core.dflowfm.polyfile.models.PolyFile and the meshkernel.GeometryList() are convertible to each other (or if the classes are aligned with each other)

Describe alternatives you've considered
Options in the description above, but these are a bit cumbersome