fix(workflows): prevent dialogs from overlapping sidebar

When the "fix thread actions" option is enabled, we apply some styling
which makes the workflow dialogs overlap the sidebar/header.

This CL makes the sidebar appear behind the dialog scrim by changing the
z-index of the thread actions toolbar. The header still appears appears
above the scrim, but it's a tradeoff because otherwise the toolbar would
appear above the header when scrolling down and that's worse.

Fixed: twpowertools:150
Change-Id: I3fae699dcd1c2391ba5235f781cc5af37ef5e47c
diff --git a/src/contentScripts/communityConsole/main.js b/src/contentScripts/communityConsole/main.js
index af69cbe..b2ad615 100644
--- a/src/contentScripts/communityConsole/main.js
+++ b/src/contentScripts/communityConsole/main.js
@@ -299,7 +299,7 @@
   // TODO(avm99963): The following features are not dynamic. Make them be.
   if (options.fixedtoolbar) {
     injectStyles(
-        'ec-bulk-actions{position: sticky; top: 0; background: var(--TWPT-primary-background, #fff); z-index: 96;}');
+        'ec-bulk-actions{position: sticky; top: 0; background: var(--TWPT-primary-background, #fff); z-index: 99;}');
   }
 
   if (options.increasecontrast) {