[WIP] - Convention Tests Polishing

- [x] wireup in CI build script
- [x] descriptive error for "the observable interface is missing"
- [x] descriptive error for "interfaces have different methods"
- [ ] descriptive error for "methods do not have same parameter count"
- [ ] descriptive error for "methods do not have same parameters"
- [ ] descriptive error for "methods do not have correct return value"