Signup/Login + styling adjustments

- Modified SearchBar styling
- Modified TopBar to display blank circle if the user has no networks (previously missing image icon)
- Refactored Login into AuthPage.js
- AuthPage contains a tab selector for switching between Signup and Login
- Both Login/Signup send the request and either receive an auth_token or an error message
- If auth_token, user will be logged in as usual, in both cases
- Signup validates user input before sending request
- Added /signup target in vite config file

vite.config.ts

@@ -20,6 +20,10 @@ export default defineConfig({
         target: "http://localhost:10002",
         changeOrigin: true
       },
+      "/signup": {
+        target: "http://localhost:10002",
+        changeOrigin: true
+      },
       "/profile": {
         target: "http://localhost:10002",
         changeOrigin: true