AutocompleteFilter component

JSP Genesys makes use of autocompleters for various fields that can be autocompleted: holder institute code, genus, etc.

Implement a new AutocompleteFilter component based on StringArrFilter (because it's the same kind of logic) that can be used for holder.code and taxa.genus filters. Text typed into the field should call the API for suggestions and render the term label and count, but use the term code in the filter.

New API endpoints need to be added to AccessionController (or a new controller?) that will accept the search text and the currently applied filters.

@mborodenko There are existing /json controllers that handle this.