feat: poll api

[rwiker]

New methods poll and poll_async. These are meant to be used with long-running requests that run asynchronously; the response from these requests include the headers Location and Retry-After that tell the client where to look for the result of the request, and how long to wait before checking for a result.

Example:

def get_index_orphans(conn: SumoClient):
    res = conn.get("/admin/index/orphans")
    res2  = conn.poll(res)
    assert res2.status_code == 200
    indexorphans = res2.json()
    assert type(indexorphans) == list

[equinor-ruaj]

lgtm, but tests seems to disagree

[equinor-ruaj]

👍