Add workflow menu to thread lists

This CL adds a MD3 menu button to the bulk actions bar in thread lists.
The menu will display the available workflows, but as of now it just
contains random items, and clicking the items doesn't work (this will be
implemented later).

This implementation has been done using the newly added @material/web
package, so the elix package has been removed from the project. This is
because @material/web also uses Material Design like the Community
Console.

Bug: twpowertools:74
Change-Id: Ifb3712c7afc024e21c7ff83fb77658cd8d08bc8a
diff --git a/src/contentScripts/communityConsole/utils/common.js b/src/contentScripts/communityConsole/utils/common.js
index 2e33f99..052b580 100644
--- a/src/contentScripts/communityConsole/utils/common.js
+++ b/src/contentScripts/communityConsole/utils/common.js
@@ -31,6 +31,19 @@
   return [badge, badgeTooltip];
 }
 
+// Adds an element to the thread list actions bar next to the button given by
+// |originalBtn|.
+export function addElementToThreadListActions(originalBtn, element) {
+  var duplicateBtn =
+      originalBtn.parentNode.querySelector('[debugid="mark-duplicate-button"]');
+  if (duplicateBtn)
+    duplicateBtn.parentNode.insertBefore(
+        element, (duplicateBtn.nextSibling || duplicateBtn));
+  else
+    originalBtn.parentNode.insertBefore(
+        element, (originalBtn.nextSibling || originalBtn));
+}
+
 // Adds a button to the thread list actions bar next to the button given by
 // |originalBtn|. The button will have icon |icon|, when hovered it will display
 // |tooltip|, and will have a debugid attribute with value |debugId|.
@@ -46,14 +59,7 @@
   [badge, badgeTooltip] = createExtBadge();
   clone.append(badge);
 
-  var duplicateBtn =
-      originalBtn.parentNode.querySelector('[debugid="mark-duplicate-button"]');
-  if (duplicateBtn)
-    duplicateBtn.parentNode.insertBefore(
-        clone, (duplicateBtn.nextSibling || duplicateBtn));
-  else
-    originalBtn.parentNode.insertBefore(
-        clone, (originalBtn.nextSibling || originalBtn));
+  addElementToThreadListActions(originalBtn, clone);
 
   createPlainTooltip(clone, tooltip);
   new MDCTooltip(badgeTooltip);