[BUG] Storage Units Plotting Error

[MoritzSchloesser]

Bug Report: Storage Units Plotting Error in plots.mv_grid_topology()

Describe the bug
The function plots.mv_grid_topology() currently creates a geoplot only for the MV grid. To achieve this, a PyPSANetwork for the MV part is created in plots.py at line 557.

However, in lines 754 to 759, the function attempts to plot storage units. The issue arises because the function tries to plot storage units from both the MV and LV grids, even though only the MV grid PyPSANetwork is available. Since all storage unit indices (including LV storage units) are passed to the MV PyPSANetwork, an error occurs.

To Reproduce
Steps to reproduce the behavior:

1. Call plots.mv_grid_topology() on a grid that contains storage units in both the MV and LV grids.
2. Observe that the function attempts to plot all storage units, including those in the LV grid.
3. Since the MV PyPSANetwork does not contain LV storage units, an error occurs.

Expected behavior
The function should only pass MV storage units to the plot function to avoid errors. Filtering the storage units before passing them to the plot function should resolve this issue.

Screenshots
(If applicable, add screenshots to help illustrate the issue.)

Additional context
Adding a filter to ensure only MV storage units are included in the plotting function will prevent this error and ensure correct visualization.