Workflows: add mark as read/unread actions

Fixed: twpowertools:147
Change-Id: I6bb2363256cfd2a0ff3aafb4df71f24561576b27
diff --git a/src/contentScripts/communityConsole/workflows/models/thread.js b/src/contentScripts/communityConsole/workflows/models/thread.js
index 0f54316..96f69de 100644
--- a/src/contentScripts/communityConsole/workflows/models/thread.js
+++ b/src/contentScripts/communityConsole/workflows/models/thread.js
@@ -97,6 +97,10 @@
     return this._details?.['2']?.['9'];
   }
 
+  get lastMessageId() {
+    return this._details?.['2']?.['10'];
+  }
+
   get payload() {
     return this._details?.['2']?.['13'];
   }