only show the scroll top top of activity feed button when the user has scroll passed the top of the window

This reverts commit c0ed1fff.

adding window resize method to reset the mobile filters if they're left open past the tablet breakpoint

add active class to select2 checkboxes after page has been filtered, as the classes that had been added are stripped after filtering

show list of selected files for upload to input file type labels as the actual input is being hidden along with the filenames

refactor mobile search button when the mobile menu is open, to close the mobile menu and then open the search form