Feature/7993 update get downloadable fields

[NekoLyn]

API: /collections/:uuid/items/wms_fields?layerName=xxx

• get map layer fields for map tools/map tiles query/map features from its describe layer
• layername is optional. If no layername is provided then return all the fields for all wms links in the collection

example res for uuid = 06b09398-d3d0-47dc-a54a-a745319fbece:

[
    {
        "typename": "aatams_sattag_dm_profile_map",
        "fields": [
            {
                "label": "profile_id",
                "name": "profile_id",
                "type": "long"
            },
            {
                "label": "file_id",
                "name": "file_id",
                "type": "long"
            },
          ... ...
            {
                "label": "geom",
                "name": "geom",
                "type": "GeometryPropertyType"
            },
            {
                "label": "colour",
                "name": "colour",
                "type": "string"
            },
            {
                "label": "size",
                "name": "size",
                "type": "double"
            }
        ]
    }
]

API: /collections/:uuid/items/wfs_fields?layerName=xxx

• get downloadable fields for wfs data subsetting
• layername is optional. If no layername is provided then return all the fields for all wfs links in the collection

example res for uuid = 199394010:

[
    {
        "typename": "underway_60",
        "fields": [
            {
                "label": "id",
                "name": "id",
                "type": "long"
            },
            {
                "label": "set_code",
                "name": "set_code",
                "type": "string"
            },
         ... ...
            {
                "label": "wtr_depth_m",
                "name": "wtr_depth_m",
                "type": "double"
            },
            {
                "label": "wtr_temp_optode_degc",
                "name": "wtr_temp_optode_degc",
                "type": "double"
            }
        ]
    },
    {
        "typename": "underway_1200",
        "fields": [... ...]
    },
    {
        "typename": "underway_7200",
      "fields": [... ...]
    },
    {
        "typename": "underway_mln_1200",
        "fields": [
            {
                "label": "set_code",
                "name": "set_code",
                "type": "string"
            },
            {
                "label": "min_date_time_utc",
                "name": "min_date_time_utc",
                "type": "dateTime"
            },
            {
                "label": "max_date_time_utc",
                "name": "max_date_time_utc",
                "type": "dateTime"
            },
            {
                "label": "voyage",
                "name": "voyage",
                "type": "MultiCurvePropertyType"
            }
        ]
    }
]

[utas-raymondng]

LGTM