[core] Add the document copy action to the right click context menu in the documents page

This adds the "copy" action to the context menu for documents listed in the documents page. Before this change it was only available in the upper right actions menu.

desktop/core/src/desktop/templates/document_browser.mako

@@ -302,6 +302,9 @@ else:
                 <li data-bind="css: { 'disabled': $parent.selectedEntries().length !== 1 }"><a href="javascript:void(0);" data-bind="click: showRenameDirectoryModal, css: { 'disabled': $parent.selectedEntries().length !== 1 }"><i class="fa fa-fw fa-edit"></i> ${ _('Rename') }</a></li>
                 <!-- /ko -->
                 <li data-bind="css: { 'disabled': $parent.selectedEntries().length !== 1 }"><a href="javascript:void(0);" data-bind="click: open, css: { 'disabled': $parent.selectedEntries().length !== 1 }"><i class="fa fa-fw fa-file-o"></i> ${ _('Open') }</a></li>
+                <li data-bind="css: { 'disabled': isDirectory() || isTrashed() }">
+                  <a href="javascript:void(0);" data-bind="click: function () { $parent.copy()  }, css: { 'disabled': isDirectory() || isTrashed() }"><i class="fa fa-fw fa-files-o"></i> ${_('Copy')} <span data-bind="visible: $parent.selectedEntries().length > 1, text: '(' + $parent.selectedEntries().length + ')'"></span></a>
+                </li>
                 <li><a href="javascript:void(0);" data-bind="click: contextMenuDownload"><i class="fa fa-fw fa-download"></i> ${ _('Download') } <span data-bind="visible: $parent.selectedEntries().length > 1, text: '(' + $parent.selectedEntries().length + ')'"></span></a></li>
                 <li data-bind="css: { 'disabled' : $parent.sharedWithMeSelected()  && ! $parent.superuser }"><a href="javascript:void(0);" data-bind="click: function () { huePubSub.publish('doc.show.delete.modal', $parent); }, css: { 'disabled' : $parent.sharedWithMeSelected() && ! $parent.superuser }">
                   <i class="fa fa-fw fa-times"></i> ${ _('Move to trash') } <span data-bind="visible: $parent.selectedEntries().length > 1, text: '(' + $parent.selectedEntries().length + ')'"></span></a>