feat: A/B test support for new tutorial

[aixaCode]

What?

Adding support for new tutorial_variant feature flag to A/B test the new flow

Why?

To support A/B test we need to be compatible with https://adr.decentraland.org/adr/ADR-73 and use variant to distinguish the cohort we are targeting.

[github-actions[bot]]

Test this pull request

• This branch can be previewed at https://play.decentraland.zone/?kernel-branch=feat/new-tutorial-feature-flag
• The @dcl/kernel package can be tested in scenes by running

  npm install "https://sdk-team-cdn.decentraland.org/@dcl/kernel/branch/feat/new-tutorial-feature-flag/dcl-kernel-2.0.0-3931438123.commit-70db775.tgz"