feat(filtered_search): Implement filtered search suggestions

This is first MR in series, to implement filtered search component This MR implement suggestion list component, which is controlled via external events (filtered search uses it to control suggestions next to input)

For overall filtered search architecture see !982 (merged)

This component is built in mind to be abstracted for more use cases (autocomplete is known scenario in GitLab), but please let's keep it focused on filtered search demands for now