[tests] log a TestException instead of RuntimeException

[jukzi]

nightly logfile is flooded with intentional RuntimeException that are hard to distinguish from unintentional exceptions.

[akurtakov]

There is smth I don't understand here - What's the point in throwing this custom exception if nothing catches/checks it ? Wouldn't it be the same to not throw anything at all?

[jukzi]

It will be logged as "TestException", and when i read the logfile i do not need to dig into if its a real failure. Is there any mechanisms that can prevent such errors from being logged? that would be even better.
As far as i understand those Tests tests that it works even if a customer throws an exception. The exceptions are catched and logged only.

[github-actions]

Test Results

 1 815 files  ±0   1 815 suites  ±0   1h 33m 10s ⏱️ - 7m 44s
 7 704 tests ±0   7 476 ✅ ±0  228 💤 ±0  0 ❌ ±0 
24 273 runs  ±0  23 526 ✅ ±0  747 💤 ±0  0 ❌ ±0 

Results for commit 40e6a8e. ± Comparison against base commit cc770ec.