Combine multiple test results

With the current implementation in place splitting single test in several executions can only happen from within Arquillian events (so we run n tests from within single test). This in particular happens for running contract tests for Pact, where one test spawns several verifications based on the content of the contract itself.

Even though the List<TestResult> is used as a container object for TestResult instance passed along when Test event is fired, it can happen one test can be fired multiple times (for example in arquillian-algeron).

The temporary solution for this problem could be that all the results are collected into one instance of TestResult.