[WebIDE] improve local integration setup with GitLab Rails app

Problem to solve

Currently, setting up local integration of the Web IDE with the GitLab Rails app requires creating a MR to deploy VS Code Workbench assets to the staging static host.

This impacts developer workflow by requiring an MR, a pipeline run for every change pushed to test, making the integration testing less efficient.

Proposed solution

1. Set up yalc to dynamically link the Web IDE npm package to the GDK.
2. Set up Content Security Policy rules in the GDK to allow embedding the Web IDE's local server in the GitLab Rails application.

Acceptance criteria

• Can dynamically apply WebIDE changes in the GitLab Rails app