Support jira.devstatus.applink.ratelimit also on GitHub

Description:

Today depending on how big an instance is we can easily hit a rate limit imposed by GitHub and this could block the ability to perform DVCS full-Sync in Jira

Suggested Solution:

The suggestion here is to deliver jira.devstatus.applink.ratelimit to GitHub integration so we can give a small delay between calls we do against GitHub, generating then the possibility to perform a full-sync even on instances with a large number of repos/branches/commits, etc.

As an additional suggestion, would be good to focus on this approach, or at least give the option in HOW we want to configure this parameter in Jira, since it can cause a general degradation, it could impact other functions like how the development panel is loaded would be good to mainly point it to sync transaction if possible.