Switch EditorContextMenu back to using popup instead of exec (#1158)

Switch EditorContextMenu back to using popup instead of exec

The switch to exec was a deliberate change, but upon further testing with the latest version of our camera input controllers (both the Legacy and Modern variants) it is no longer necessary to call exec, and doing so can cause a bug in which the cursor is still hidden when the context menu appears.

Code/Framework/AzToolsFramework/AzToolsFramework/Viewport/EditorContextMenu.cpp

@@ -62,7 +62,8 @@ namespace AzToolsFramework
 
                 if (!contextMenu.m_menu->isEmpty())
                 {
-                    contextMenu.m_menu->exec(QCursor::pos());
+                    // Use popup instead of exec; this avoids blocking input event processing while the menu dialog is active
+                    contextMenu.m_menu->popup(QCursor::pos());
                 }
             }
         }