Use rake to start the test suite in Jenkins

While we worked on the vagrant build switch part of #5630 (closed) (#11972 (closed) and friends), the Rakefile got improved with some code that can be used to start the test suite through rake test.

There’s been a pull request to use switch to this in Jenkins.

Related issues

Related to #11972 (closed)

Original created by @bertagaz on 12503 (Redmine)

To upload designs, you'll need to enable LFS and have an admin enable hashed storage. More information