Add LDAP group membership management to the Directory modal, pin Groups sort bar, merge Directory columns

- Directory modal's Associated LDAP Groups tab now lets you view/add/remove
  members and owners of each associated group directly, reusing the same
  PUT/DELETE group/:group/:uid routes and member-mapping pattern already
  used on the Groups page -- no backend change needed.
- Groups page: the search/sort bar is now sticky, staying visible while
  scrolling through a long group list. Introduces --sw-content-offset (set
  in top.ejs alongside #spa-shell's margin-top) so an in-page sticky
  element can offset itself below the fixed navbar/update-banner instead
  of being hidden behind them at the viewport's true top:0.
- Directory table: Kind/Name/Env/Host merged into a single "Resource"
  column, matching the same information more compactly.
- app-base.js (byte-identical across the 3 apps): added app.util.revealItem(),
  which scrolls a just-added/-edited element into view and flashes its
  background -- wired into the Directory table, the Groups tab's member
  list, and the Groups page's create-group flow.
- Bumped @simpleworkjs/frontend to ^0.2.7 (published with the same
  revealItem() addition for any future consumer of its app.js, even though
  none of the 3 apps currently load that file directly -- they use the
  legacy app-base.js instead).

nodejs/views/top.ejs

@@ -82,16 +82,24 @@
 		</div>
 
 		<script type="text/javascript">
+			// --sw-content-offset tracks the same height as #spa-shell's margin-top
+			// (fixed navbar, plus the update banner while it's shown), so any
+			// in-page sticky element (e.g. a sticky search/sort bar) can offset
+			// itself below both fixed elements via `top: var(--sw-content-offset)`
+			// instead of colliding with them at the viewport's true top:0.
 			function showUpdateBanner(){
 				let $nav = $('nav.fixed-top');
 				let $banner = $('#update-banner');
 				$banner.css('top', $nav.outerHeight() + 'px').show();
-				$('#spa-shell').css('margin-top', ($nav.outerHeight() + $banner.outerHeight()) + 'px');
+				let offset = $nav.outerHeight() + $banner.outerHeight();
+				$('#spa-shell').css('margin-top', offset + 'px');
+				document.documentElement.style.setProperty('--sw-content-offset', offset + 'px');
 			}
 
 			function dismissUpdateBanner(){
 				$('#update-banner').hide();
 				$('#spa-shell').css('margin-top', '');
+				document.documentElement.style.setProperty('--sw-content-offset', $('nav.fixed-top').outerHeight() + 'px');
 				sessionStorage.setItem('update-banner-dismissed', '1');
 			}