Update to Heroicons v2

[driesvints]

We'll need to make sure all icons still work as some have gotten different names.

[thinkverse]

Have a working branch locally, and wanted to get your opinion on how which icons to use. The menu bar and x icon look pretty much the same. The save button is drastically different, and the reset icon looks also pretty much the same just thinner.

Maybe go with the folder plus one instead? Seems more uniform in v2?

[driesvints]

@thinkverse yes. I agree, feel free to update that and ping me. Thanks!