Return an array where each entry is an object with this form:

{ source: "fitbit", name: "Fitbit", usernames: ["beau", "madprime"] }

GET /api/public-data/members-by-source/?source=direct-sharing-514
HTTP 200 OK
Allow: GET, HEAD, OPTIONS
Cache-Control: max-age=0, no-cache, no-store, must-revalidate
Content-Type: application/json
Expires: Fri, 03 Feb 2023 06:19:57 GMT
Vary: Accept

{
    "count": 47,
    "next": null,
    "previous": null,
    "results": [
        {
            "source": "direct-sharing-514",
            "name": "Transbiome",
            "usernames": [
                "Julie",
                "Morpheus",
                "azalea",
                "clara_lehenaff",
                "Hela",
                "Aurore",
                "Lison",
                "alwena",
                "Alexandra",
                "Emy_p",
                "Johanne",
                "M_m",
                "Mag2021",
                "Jessie",
                "miss_c",
                "Core_Persephone",
                "Kwadratschaedel",
                "Lau",
                "RoseIDE88",
                "selfawaresoup",
                "KATIUSKA",
                "Bertocchio",
                "Nathasha",
                "Lou",
                "Cecile_du_22",
                "fannyomally",
                "marie34",
                "Gabrielle",
                "Bloboloblob",
                "Vlasta",
                "Sophiel",
                "jessie0o0"
            ]
        }
    ]
}