integrate copilot UI with backend (#1478)

src/Explorer/SplashScreen/SplashScreen.tsx

@@ -137,7 +137,7 @@ export class SplashScreen extends React.Component<SplashScreenProps> {
               description={
                 "Copilot is your AI buddy that helps you write Azure Cosmos DB queries like a pro. Try it using our sample data set now!"
               }
-              onClick={() => useCarousel.getState().setShowCopilotCarousel(true)}
+              onClick={() => useTabs.getState().openAndActivateReactTab(ReactTabKind.QueryCopilot)}
             />
             <SplashScreenButton
               imgSrc={ConnectIcon}