Alternative approach to using JsonSchema.NET's global schema registry class for reference resolution

[MaggieKimani1]

Currently, we use JsonSchema.NET's global SchemaRegistry class to resolve any $refs present in a JSON schema as per documentation: https://docs.json-everything.net/schema/basics/#schema-ref-resolution
However, this brings about a conflict in a scenario where we're trying to register OpenAPI files from different sovereign clouds with similar schema models. Holding two different cloud versions in memory might bring about a naming clash or the schema models will end up overriding each other which corrupts the resulting files.

[MaggieKimani1]

Closing this in favor of #805