* Allow installing `yarn` via `corepack` on Debian-based systems, too

The default behavior remains unchanged, but users can now opt-out from the APT-based installation to get the latest `yarn` via `corepack`.

Closes #1004

* Update src/node/devcontainer-feature.json
Co-authored-by: Samruddhi Khandale <samruddhikhandale@github.com>

* Update src/node/devcontainer-feature.json
Co-authored-by: Samruddhi Khandale <samruddhikhandale@github.com>

* Rename variable

* Expand comment

* Add test scenario

* Improve tests

* Update test/node/debian_yarn_from_corepack.sh

* Betetr comments

* Update src/node/devcontainer-feature.json

---------
Co-authored-by: Samruddhi Khandale <samruddhikhandale@github.com>