Add flattenthreads experiment

This experiment allows users to flatten the replies in threads, so they
are shown linearly in a chronological way instead of nested.

When the option is enabled, a switch is added to the thread page which
lets the user switch between flattening replies and not flattening them.

Some UI is still missing (see the design document[1]).

[1]: https://docs.google.com/document/d/1P-HanTHxaOFF_FHh0uSv0GIhG1dxWTJTGoT6VPjjvY0/edit

Bug: twpowertools:153
Change-Id: I43f94442cadc12b752700f0e8d974522be621d3e
diff --git a/templates/manifest.gjson b/templates/manifest.gjson
index 41d39e2..c8d2ffb 100644
--- a/templates/manifest.gjson
+++ b/templates/manifest.gjson
@@ -84,7 +84,7 @@
         "batchLockInject.bundle.js",
         "xhrInterceptorInject.bundle.js",
         "extraInfoInject.bundle.js",
-        "workflowComponentsInject.bundle.js",
+        "litComponentsInject.bundle.js",
 
         "css/profileindicator_inject.css",
         "css/ccdarktheme.css",
@@ -101,6 +101,7 @@
         "css/ui_spacing/console.css",
         "css/ui_spacing/twbasic.css",
         "css/thread_page_design_warning.css",
+        "css/thread_toolbar.css",
 
         "communityConsoleMain.bundle.js.map",
         "communityConsoleStart.bundle.js.map",