feat(cli): Add generator config, oauth and addtional properties to dynamic IR

[amckinney]

This adds a few new fields to the dynamic IR:

1. Add the GeneratorConfig as an optional property to the dynamic IR.
   • This will make it simpler to generate dynamic snippets in the front-end.
2. OAuth configuration for the client credentials flow.
   • For now, we reserve the OAuth name, but it's easy for us to roll out additional OAuth configuration options later (e.g. OAuthAuthorizationCode, etc).
3. Types now know whether or not they support additionalProperties (which is based on the extra-properties setting).
   • This opts to use the new naming convention given that we plan to update the extra-properties name in the future.
4. Add pathParameters to the top-level of the dynamic IR.
   • For now, all path parameters are included in the endpoint, but we'll update this behavior so that we only include the service-level and endpoint-level path parameters there.
   • Several test definitions will temporarily be broken from this change - these failures will be resolved in a follow-up when we migrate each dynamic snippet generator to the latest IR.