Make root:Packages:igortest:FailedProcWave less verbose

[Garados007]

This wave is used to collect a short message from each failed assertion during the test run and output them at the end as a small summary. As we do only add new information to the wave there are some circumstances now that the wave contains no longer needed information:

• After the introduction of re-running flaky tests the wave contains the output of previous failed runs. I think we don't need them in the summary and therefore these can be removed.
• The test experiment TestResultsTests has many intentionally failed tests. There is no need for these errors in the summary.

This can be fixed by storing the number of entries in FailedProcWave at the start of each test case and add a internal function that resets the wave to these number of entries.