Add welcome popop for query copilot (#1493)

src/Explorer/QueryCopilot/__snapshots__/QueryCopilotTab.test.tsx.snap

@@ -126,6 +126,9 @@ exports[`Query copilot tab snapshot test should render with initial input 1`] =
       />
     </t>
   </Stack>
+  <WelcomeModal
+    visible={true}
+  />
   <CopyPopup
     setShowCopyPopup={[Function]}
     showCopyPopup={false}