Zotero.SearchQuery turns a query like `by:smith after:2020 tag:"to read"
crispr` or `creator is smith and (tag is foo or bar)` into a
Zotero.Search, matching whatever text is left over using the current
search mode. Anything that doesn't look like a clause is free text, so a
DOI or a title with a colon in it is matched literally.
The search box syntax-highlights the parts of recognized conditions and
offers autocomplete for condition names, for the values of conditions
that have a fixed set of them (like item type), and for tags and
creators from the selected libraries.
