4088: use filterable.js to filter on client side
Implemented client-side filtering via filterable.js:
* Designated filename rows as "filterable"
* Designated filename pattern input field as "filterable-control"
* Added "Select all" and "Unselect all" buttons with matching
select_all_files() and unselect_all_files() actions
* Limit selection actions (compare, move, copy etc) to visible page
elements only.
* Added integration tests "Filtering collection files by regexp" and
"Creating collection from list of filtered files".