URI format doesn't work with newer `ajv` lib

Expected: upgrade libs and all tests pass
Actual: Entity schema tests fails with URI format. AJV was anchored on the test suite at 6.12.5. Upgrade breaks the test.

```
Valid Entity Schema Test:
Error: unknown format "uri" ignored in schema at path "#/definitions/image/properties/uri"
```
Recent AJV lib 8.12.0 does not permit uri as schema format, and test will fail.

```
- "ajv": "^8.12.0",
+ "ajv": "^6.12.5",
```

Suggested fixes:

- Reformat format path as regex, so preformat rules aren't a problem.
- Possibly an issue with ajv implementation. Might have updated to need to use https://github.com/ajv-validator/ajv-formats
- Check if JSONSchema spec actually updated directly, such that it doesn't support `uri` format anymore.