Improved Indexer Backoff and Status handling logic

[ghost]

As per Sonarr/Sonarr#3132

I run an indexer and my API is hammered by users who exceed their daily API limits. It would be great if Medusa could use and respect the API usage/limits shown when calling the capabilities or search endpoints.

?t=caps
<limits max="100" default="100"/>

?t=search
<newznab:apilimits apicurrent="485" apimax="500" grabcurrent="142" grabmax="500" apioldesttime="Thu, 03 Feb 2022 15:16:03 +0100" graboldesttime="Thu, 03 Feb 2022 15:19:35 +0100"/>