Frontend: Provide a more helpful error messages in places where the user is rate-limited.

The following discussion from !96133 (merged) should be addressed:

  • @manojmj started a discussion: (+1 comment)

    Note: On hitting the rate limit, the groups create page currently responds with:

    Screenshot_2022-08-24_at_1.02.40_PM

    which is the same error you'd get in case of 500 error.

    The same behaviour is also exhibited in the user sign up page, where the username suggestor endpoint is rate limited.

    Screenshot_2022-08-24_at_1.00.39_PM

    I think we have an opportunity in the frontend to refine these error messages to communicate that you are being rate limited, please try after <interval>, instead of a generic error. Probably the frontend could check the response code and if it is 429 (which is what rate limiter responds with on reaching the threshold), a different, more transparent error message can be shown, which would be more helpful to the end user? This could be a follow up.

    WDYT @peterhegman 🙂