frontend: show _all_ build checkboxes by javascript
    
    This complements b866853e2286cbb8f0d58c3e2e0eb772336da97e.  The original
    commit caused a problem that at the time when the whole page document
    was loaded - the script responsible for hiding (removing) the javascript
    table nodes were already executed.  So the hack
    
        `$(".show-me-javascript").removeClass("hidden")`
    
    .. only affected a subset of targeted elements (only those which were
    currently rendered).
    
    Then, hitting the pagination javascript buttons caused that other nodes
    appeared again, but with the (not removed) "hidden" class (so they were
    rendered, but invisible).
    
    So now, apply the same hack _before_ we start removing the html nodes by
    javascript so all nodes are affected.  Also keep the hack at the bottom
    of the page (we may use this idiom on other places not really depending
    on the javascript table).
    
    Resolves: rhbz#1846037