Improve ratelimit exception handling

> [!NOTE]
> Migrated from [augurlabs/augur#3037](https://github.com/augurlabs/augur/issues/3037)
> Originally opened by `@ABrain7710` on 2025-03-05

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* Raise SecordaryRateLimitException and handle it separately from regular rate limit exception
* Sleep 5 seconds longer than the retry after
* Log when retry after header or rate limit header are not set

Start by locating the rate-limit exception definitions and the retry handling that reads the Retry-After and rate-limit headers. Check the existing tests around retries, then verify that secondary limits are handled separately, retries sleep five seconds beyond the header value, and missing headers are logged.

Written by the indexing model from the issue text.