make the response content of a failed api call available to an exception handler

[uedvt359]

when an api request fails, currently we simply get the http status code. this is not very descriptive, and i'd like to inspect the json response for the error message. this patch allows this.

this allows for the following code:

    try:
        vaultwarden_client.api_request(...)
    except httpx.HTTPStatusError as e:
        print(e.response.json()["message"]) # e.g. "No rights to modify the collection", instead of just "400".