fix: auto save ui and env var (#3384)

* Added new confirmation modal for saving

* Fixed save button

* fixed header classes

* updated docs link

* Added different message to auto saving

* Changed tooltip to appear in saved text, not in button

* Changed tooltip back to previous when auto saving is enabled

* changed auto_save to auto_saving

* Fixed build not appearing and icons

* Changed modal when autosave is enabled

* 🐛 (menuBar/index.tsx): fix condition for disabling save button to include isBuilding flag to prevent saving during build process

* fix current flow not being updated on set nodes and edges and fix modal not letting user leave when flow is empty

* Removed console log

* Fix add flow not adding the flow that comes from the backend

---------

Co-authored-by: cristhianzl <cristhian.lousa@gmail.com>
Co-authored-by: Cristhian Zanforlin Lousa <72977554+Cristhianzl@users.noreply.github.com>

src/frontend/vite.config.mts

@@ -31,8 +31,8 @@ export default defineConfig(({ mode }) => {
       outDir: "build",
     },
     define: {
-      "process.env.LANGFLOW_AUTO_SAVE": JSON.stringify(
-        process.env.LANGFLOW_AUTO_SAVE,
+      "process.env.LANGFLOW_AUTO_SAVING": JSON.stringify(
+        process.env.LANGFLOW_AUTO_SAVING,
       ),
       "process.env.BACKEND_URL": JSON.stringify(process.env.BACKEND_URL),
       "process.env.ACCESS_TOKEN_EXPIRE_SECONDS": JSON.stringify(