Resolve "Improve test environment to use seperate ceos instance for each pipeline"

Terraform key dynamisch setzen: https://docs.gitlab.com/ee/ci/yaml/#cachekey

Und eigener job, der initial den port wuerfelt und ihn als artifact uebergibt.

Description

Related Issue

Motivation and Context

How Has This Been Tested?

Screenshots (if appropriate):

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)

Checklist:

• My code follows the code style of this project.
• My change requires a change to the documentation.
• I have updated the documentation accordingly.
• I have read the CONTRIBUTING document.
• I have added tests to cover my changes.
• All new and existing tests passed.

Closes #112 (closed)