Thank you for asking. We maintain a list of public icons on https://barista.dynatrace.com/resources/icons. Not all icons that you see in Dynatrace are publicly available though - so you might not find everything that you are used to seeing in Dynatrace.
We also ship those icons inside the barista-icons package on npm https://www.npmjs.com/package/@dynatrace/barista-icons
Let me know if I can help you in any other way.