feature: ingtegration test coverage

[hsinn0]

• Modified cargo.local to run with jacoco agent if a system property is set.
• Added a task to generate coverage report from the recorded jacoco data.

Gradle console output:

> Task :jacocoLogCargoCoverage
Test Coverage:
    - Class Coverage: 79.5%
    - Method Coverage: 67.2%
    - Branch Coverage: 42.4%
    - Line Coverage: 64.3%
    - Instruction Coverage: 61.6%
    - Complexity Coverage: 45.7%

[strehle]

not yet adopted the sonar... but in future we should combine unit and integration tests in one run and then coverage in https://sonarcloud.io/summary/overall?id=cloudfoundry-identity-parent should increase

thanks