prevent gdi error at 10k items

[Hofknecht]

related to #234
can we count gdi objects like here
https://www.syncfusion.com/faq/windowsforms/drawing-tips/how-do-i-get-a-count-of-the-gdi-handles-currently-in-use-in-my-application
and if we reached e.g. 5k do not load any more icons or clear cache?

I'm not sure if that's a nice solution, clear cache isn't enough if the main menu had 10k+ items, you would always have to stop the icons from loading. But if you want that, you've done something wrong anyway if you have 10k+ items in the main menu?

or maybe dgv virtual mode, does this help? That we only load icons for visible rows and dispose as soon it gets invisible?

Maybe something for later