## Description
Having a map of interface values instead of concrete structs allows adding collection implementations via different structs. This will be useful to inject a new collection that contains metadata information like delta links.
Also refactors the code for creating collections in Exchange so that it follows golang patterns of exiting early a bit better.
## Type of change
<!--- Please check the type of change your PR introduces: --->
- [ ] 🌻 Feature
- [ ] 🐛 Bugfix
- [ ] 🗺️ Documentation
- [ ] 🤖 Test
- [ ] 💻 CI/Deployment
- [x] 🐹 Trivial/Minor
## Issue(s)
* #1685
## Test Plan
<!-- How will this be tested prior to merging.-->
- [ ] 💪 Manual
- [x] ⚡ Unit test
- [ ] 💚 E2E
55a03af95f