Fix repositery workdir NodeJS app for Dockerfile

[jorisvilardell]

This pull request includes several updates to the generate_and_write_dockerfile function in the src/services/helpers/docker_helper.rs file. The changes focus on improving the handling of package managers and updating the Dockerfile generation process.

Improvements to package manager handling:

• Added a print statement for unknown package managers and defaulted to using npm when an unknown package manager is detected.
• Updated the base image selection to use node:20-alpine for all recognized package managers, removing the previous special case for bun.
• Introduced a package_lock variable to handle different lock files for yarn, pnpm, and npm.

Updates to Dockerfile generation:

• Modified the Dockerfile template to include the appropriate package_lock file and adjusted the COPY commands to use the app_workdir variable.