Adapt the CI pipeline to use patch files and the VSCode upstream submodule to create builds

MR: ci: Use upstream submodule to build vscode (!86 - merged)

Description

As part of transitioning to a patch-based strategy to apply changes to the VSCode upstream repository, we want to modify the build jobs in the VSCode Fork CI pipeline to generate build artifacts based on the upstream submodule and the patch files that modify upstream.

Acceptance criteria

• build-and-bundle job uses vscode upstream submodule and patch files.
• build-server job uses vscode upstream submodule and patch files.

Reference

• RFC: Proposal to improve VSCode upgrade process (#32 - closed)
• Use patch strategy instead of force pushing to ... (#5 - closed)