Improve tags filtering

[tnajdek]

Currently we do tag filtering locally, i.e. all tags for current view are fetched and filtered by the query. We can improve this by querying the API to do the filtering, however this is currently doing case-sensitive search. Once zotero/dataserver#2 is addressed we should revisit to improve search performance.

[tnajdek]

Also should be able to request tags of a given type (i.e. only non-automatic tags)

https://forums.zotero.org/discussion/116859/web-library-spinning-wheel-after-clicking-on-show-automatic-in-the-tag-selector#latest