Bug 1887858 - What needs my attention: remove duplicate needinfos

[dklawren]

This pull request uses caches to make sure that a bug is only displayed once per page load of the attention report. The local cache is for removing duplicates for a single section and the global cache is for all sections of the page. The way the cache works is the duplicates will be removed for the lower sections which are the least important and display them in the upper more critical sections.