Enable Branch deployment in Pipelines

[Aduril]

There should be a method to create a new pipeline for a new branch within a project repository. The branch should have its own cloudfront and the data should be separated from the live environment (no shared items-bucket, for example).

• Multiple branches are allowed to share the same items bucket
• There is a test mode for deploy, that uses the branch name to deploy a separate package with its own cloudfront
• There is a way to create a new pipeline that observes a certain branch