[CI] Automate license check reviews

[marcdumais-work]

What it does

Introduce automated license check reviews

In this PR we introduce the option to use our license check tool,
"dash-licenses", in "Automatic IP Team Review Requests" mode [1].
In this mode, any dependency that's found to have an unclear or
suspicious license will be automatically submitted to the Eclipse
Foundation for review. Each such dependency will have a ticket opened
on the Foundation's Gitlab and be automatically reviewed. If the
automated review is not conclusive, a manual assessment will be
performed by the Foundation's IP team.

In our experience, most dependencies are approved automatically
within minutes.

To perform a license check with automated reviews, use the new script:

$> yarn license:check:review

To perform the license check without the automated review, do as before:

$> yarn license:check

Note: for review mode to work, a Personal Access Token from the Foundation's
Gitlab is required, created from an Eclipse committer's Gitlab profile. I went ahead and
set one as a GitHub secret, for this repo.
Set it in an environment variable named "DASH_LICENSES_PAT". E.g. in bash:

$> export DASH_LICENSES_PAT=<token>

[1] https://github.com/eclipse/dash-licenses#automatic-ip-team-review-requests

P.S. we obtained permission to do this a while ago.

How to test

• Locally, with and without a PAT set, confirm that yarn license:check still works like before
• Locally, with and without a PAT set, confirm that the new yarn license:check:review works as expected:
  • without PAT: the tool exits immediately with an error message about the missing token
  • with PAT: the tool proceeds to run and creates or points-to existing Gitlab issues about the problematic dependencies.

"btoa": "1.2.1" can be used currently as a suspicious dependency for testing purposes - add it to root package.json and run yarn

Review checklist

• As an author, I have thoroughly tested my changes and carefully followed the review guidelines

Reminder for reviewers

• As a reviewer, I agree to behave in accordance with the review guidelines

[marcdumais-work]

OOPS - I will see what I can do about yargs - It worked locally because I had the repo built I guess.

[paul-marechal]

Logic LGTM, I only pushed styling and cleanup changes.