Improve "fringy" look when plotting shaded dfsu.

[zweihuehner]

Description
When plotting a dfsu DataArray with plot_type="shaded", the triangles that lie close to elements that fell "dry" during a simulation are looking quite fringy. The underlying function is the matplotlib tripcolor in _FM_utils.py. Possibly the behavior is coming from matplotlib and can not be changed in mikeio.

To Reproduce
Load a dfsu dataset that comes from a m3fm simulation with dry falling elements. Plot a DataArray from the dataset like the following.

import mikeio
import matplotlib.pyplot as plt
ds = mikeio.read("example.dfsu")
fig, ax = plt.subplots(figsize = (14,14))
ds.Current_speed.plot(ax = ax, plot_type="shaded")

Example File:
example_dfsu.zip

Expected behavior
See a shaded plot without the fringy look of the triangle edges.

Screenshots

System information:

• Python version: 3.10.10
• MIKE IO version: 2.2.dev3