Bulk search ID checker

[denver-code]

Make a quick check if list of IDs could be represented as a list of ObjectID's

Test:

def test_bulk_search_one_valid(client):
    test_signup(client)
    token1 = client.post(
    "/api/public/authorisation/signin", 
    json={
        "email": "testuser@test.com",
        "password": "testpassword",
    }).json().get("token", "")
    user1 = client.get("/api/private/profile", headers={"Authorisation":token1}).json()

    del user1["email"]

    response = client.post("/api/public/profile/bulk",
        json={
            "users": [
                user1["id"],
                "11111891a5d13e63599968cc1"
            ]
        }
    )
    assert response.status_code == 200
    assert response.json() == [
        user1
    ]