Fixture: Adding API Key Model

[AkhileshNegi]

Is your feature request related to a problem? Please describe.
Right now, we have a superuser_api_key_headers and normal_user_api_key_headers which returns API key that can be used in test cases when validating requests. However it only returns API key that is used in headers directly

Describe the solution you'd like
Add a new fixture that returns API key model instead of just the API key value so it gives us flexibility of using API key's project_id and organization_id