In principle, everything is available for this in Krita, including a modular system for brush icons. You can also use @TheTwo’s template for this, or create one yourself. I have created several personalized templates for my own use, but an icon with my nickname in the image might not help you. 
If you click on “Load from Icon Library” you can click-build your Icon
And as you can see in this screenshot, you can also add own icons to those Krita has on its own/is shipped with.
Link to the template from @TheTwo →
Michelist