Fix frontend build with Angular 16 and update Sprint Boot to version 2

[pyby]

Motivation and Context

The frontend was too old. It has to be replaced.

Description

• Use Node 20.8.0 and npm 10.2.1 to build the frontend app.
• Updated application in portal-app folder with AngularJS 16.2.0.
• Upgrade to Sprint Boot to 2.7.17.
• Add WebMvcConfig to serve frontend app pages. Thanks @jboix.
• Replace custom login page with the default loginForm from SprintBoot. Thanks @jboix.
• Add .editorconfig at root to be used in both projects.
• Add Android application custom requests in code and unit tests, not in read me.
• Unit tests are running with mvn clean test.

Checklist

• [x] The branch has been rebased onto the main branch.
• [x] The green check mark "All checks have passed" is displayed on the PR.
• [x] The documentation has been updated (if relevant).
• [x] Issues are linked to the PR, if any.

[pyby]

• Unit tests run again on CI and pass.
• Play Android application custom requests are supported.
• Cache for api/v2/deeplink/parsePlayUrl.js is working.