[UI] Web Prefix (#9334)

* [UI] Change default web prefix

- Adjust default from "platform" to "web"
- Much more standard prefix

* Cleanup

* Fixes for playwright tests

* Fix unit tests

* Refactor base_url into getBaseUrl

codecov.yml

@@ -22,7 +22,7 @@ flag_management:
       statuses:
         - type: project
           target: 40%
-    - name: pui
+    - name: web
       carryforward: true
       statuses:
         - type: project