Added event to signal when the Editor is fully initialized so test scripts can listen for that instead of needed arbitrary wait commands. (#5623)

Signed-off-by: Chris Galvan <chgalvan@amazon.com>

Code/Editor/CryEdit.cpp

@@ -4181,6 +4181,8 @@ extern "C" int AZ_DLL_EXPORT CryEditMain(int argc, char* argv[])
             "\nThis could be because of incorrectly configured components, or missing required gems."
             "\nSee other errors for more details.");
 
+        AzToolsFramework::EditorEventsBus::Broadcast(&AzToolsFramework::EditorEvents::NotifyEditorInitialized);
+
         if (didCryEditStart)
         {
             app->EnableOnIdle();

Code/Framework/AzToolsFramework/AzToolsFramework/API/ToolsApplicationAPI.h

@@ -927,6 +927,9 @@ namespace AzToolsFramework
         /// Notify that the MainWindow has been fully initialized
         virtual void NotifyMainWindowInitialized(QMainWindow* /*mainWindow*/) {}
 
+        /// Notify that the Editor has been fully initialized
+        virtual void NotifyEditorInitialized() {}
+
         /// Signal that an asset should be highlighted / selected
         virtual void SelectAsset(const QString& /* assetPath */) {}
     };

Code/Framework/AzToolsFramework/AzToolsFramework/Application/ToolsApplication.cpp

@@ -214,12 +214,17 @@ namespace AzToolsFramework
             , public AZ::BehaviorEBusHandler
         {
             AZ_EBUS_BEHAVIOR_BINDER(EditorEventsBusHandler, "{352F80BB-469A-40B6-B322-FE57AB51E4DA}", AZ::SystemAllocator,
-                NotifyRegisterViews);
+                NotifyRegisterViews, NotifyEditorInitialized);
 
             void NotifyRegisterViews() override
             {
                 Call(FN_NotifyRegisterViews);
             }
+
+            void NotifyEditorInitialized() override
+            {
+                Call(FN_NotifyEditorInitialized);
+            }
         };
 
     } // Internal
@@ -443,6 +448,7 @@ namespace AzToolsFramework
                 ->Attribute(AZ::Script::Attributes::Module, "editor")
                 ->Handler<Internal::EditorEventsBusHandler>()
                 ->Event("NotifyRegisterViews", &EditorEvents::NotifyRegisterViews)
+                ->Event("NotifyEditorInitialized", &EditorEvents::NotifyEditorInitialized)
                 ;
 
             behaviorContext->EBus<ViewPaneCallbackBus>("ViewPaneCallbackBus")