Add GET endpoints for named places

[regetz]

What

This PR adds GET endpoints for named places, allowing clients to get this data as:

1. A single named place identified by its np_code
2. The full paginated collection of named places

It also sneaks in a few minor code comment and OpenAPI doc fixes.

Why

So that clients can get the set of named places registered in VegBank, especially for associating with their own plot observations at upload time ... if we choose to support this.

Previously we only returned named place records associated with specific plot observations, as a nested array field in the plot observation responses.

How

• Added a new NamedPlace operator
• Add relevant new routes

Testing and documentation

• Manually tested that the new endpoints work as expected
• Add complete API documentation of these new endpoints to the OpenAPI Spec doc
• Also locally uploaded vegbankr R package API integration and end-to-end tests for hitting the new endpoints, and confirmed that all tests pass

Demo

Get one named place record

$ http GET 'http://127.0.0.1:8080/named-places/np.61514'

{
    "count": 1,
    "data": [
        {
            "code": "ZION",
            "description": null,
            "name": "Zion NP",
            "np_code": "np.61514",
            "obs_count": 0,
            "owner": "US NPS",
            "rf_label": null,
            "system": "Geographic Name"
        }
    ]
}

Get the full paginated collection of named places (limit 2)

$ http GET 'http://127.0.0.1:8080/named-places?limit=2'

{
    "count": 64563,
    "data": [
        {
            "code": "f",
            "description": null,
            "name": "Africa",
            "np_code": "np.1",
            "obs_count": 0,
            "owner": null,
            "rf_label": "USLC place names",
            "system": "continent"
        },
        {
            "code": "fc",
            "description": null,
            "name": "Africa, Central",
            "np_code": "np.2",
            "obs_count": 0,
            "owner": null,
            "rf_label": "USLC place names",
            "system": "area|country|territory"
        }
    ]
}

[regetz]

Successfully deployed to the k8s dev cluster in the vegbank namespace and tested there. Merging to dev...