Matches should arrive in alphabetical order. Currently results are not
capped (JS should be able to handle ~1k tags without too much hassle),
and no reordering based on match location is done. Matches are substring
based, and multiple can be provided, eg "foo::bar" will match
"foof::baz::abbar".
This is not hooked up properly on the frontend at the moment -
updateSuggestions() seems to be missing the most recently typed character,
and is not updating the list of completions half the time.
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