test: altTester integration

[aixaCode]

What does this PR change?

...

How to test the changes?

1. Go to: https://play.decentraland.zone/?renderer-branch={branch_name}&{desired_url_params}
2. ...

Our Code Review Standards

https://github.com/decentraland/unity-renderer/blob/master/docs/code-review-standards.md

[github-actions]

After the CI passes:

• This branch can be previewed at https://play.decentraland.zone/?renderer-branch=test/alt-tester-integration
• Code coverage report: https://renderer-artifacts.decentraland.org/branch-coverage/test/alt-tester-integration
• Benchmark report: https://renderer-artifacts.decentraland.org/branch-benchmark/test/alt-tester-integration/index.html

[rucindrea]

I unintentionally closed this when I rebased and dropped all changes to start over with a clean slate.

[github-actions]

After the CI passes:

• This branch can be previewed at https://play.decentraland.zone/?renderer-branch=test/alt-tester-integration
• Code coverage report: https://renderer-artifacts.decentraland.org/branch-coverage/test/alt-tester-integration
• Benchmark report: https://renderer-artifacts.decentraland.org/branch-benchmark/test/alt-tester-integration/index.html