Make the list of fields in a response configurable

**Is your feature request related to a problem? Please describe.**
Many of the endpoints allow providing a list of fields to the request, which varies the size of the response payload (see [alarms](https://gallaghersecurity.github.io/cc-rest-docs/ref/events.html)). We should support this as part of the API calls.

**Describe the solution you'd like**
At the moment the `pyndatic` models expect all of the fields to exists, we will have to study how to temporarily relax the validation requirements of `pydantic` models. I would rather not have to duplicate the models for the two use cases.

Provide a pythonic manner to provide the list of fields (rather than strings), again we might have to lean into the pydantic models and how they make the meta data available to the application.

**Describe alternatives you've considered**
NA

**Additional context**
NA