Add Requirements to coverage measuring logic

[miroslavpojer]

Background

When the Requirements are supported by generated, they can be used as targets in test headers.

Feature

• Add support to use Requirements as a target in test headers.
• Extent coverage matrixes in generated output files
• Design idea:
  • keep the difference for (point for discussion)
    • Feature covered by tests - direct mentions
    • Feature covered by "test covered Requirements" - no direct Feature mentions in test headers