Support custom email addresses

[philschatz]

Hello!

Github allows users to Block command line pushes that expose my email but it seems gitpod does not notice that setting and instead uses my primary GitHub email when generating the workspace ~/.gitconfig file.

It seems like there are at least 2 different ways to solve this niche problem:

1. Change something like manager/create.go to allow GIT_COMMITTER_EMAIL if the user has set it in their "Variables" list
2. Change something like server/.../github-auth-provider.ts to store the email address that GitHub expects (e.g. 253202+philschatz@users.noreply.github.com) if no public emails are present.

Would either of these approaches (or some other ones) work? If so, it's probably just a couple of lines to fix but I'm happy to try making the changes!

[AlexTugarev]

Hey @philschatz,
This is a duplicate of #387.

The comprehensive approach would be to add an optional commitEmail next to the primaryEmail, so that it would be filled in for both GitHub and GitLab users.

[philschatz]

@AlexTugarev , Thanks for that feedback. I created a Pull Request (#4115) which I believe uses the comprehensive approach you mentioned.

[corneliusludmann]

Fixed with #4115