Metatag Autocomplete #177
Description
Right now, e1547 does not offer autocomplete for Metatags like the site does. The reason for that is, that the tags/autocomplete API endpoint only returns regular tags, and metatag autocomplete is implemented client side, as seen in this JS file:
https://github.com/e621ng/e621ng/blob/c4e8bbd7e3b5eb1cd11723f9a2e432325d7dc637/app/javascript/src/javascripts/autocomplete.js#L8-L19
To provide autocomplete for metatags, we can implement the same client side structure in e1547, where a metatag autocomplete is started once a tag contains a colon. The only "problem" is that our metatags wont update alongside the site.
An alternative approach would be to implement metatag autocomplete in e621ng directly, making it available server-side both for the site and our client. This is difficult, because autocomplete is living in a separate repository for performance reasons.