Exam Result Connection Tests

Tests for new ExamPerformanceConnection

**Required finished Issues**
- [x] HLF-CHAINCODE ExamResult https://github.com/upb-uc4/hlf-chaincode/issues/157
- [x] HLF-API-ExamPerformanceConnection https://github.com/upb-uc4/hlf-api/issues/166

**Tasks**
- [ ] implement test
- [ ] check pipeline / fix chaincode