Make CodeChecker server clean up after itslef even if interrupted

[furtib]

Describe the task

CodeChecker server can currently stay alive as a zombie process, if the tests are interrupted before it can be cleaned up.

Scope

• Implement CodeChecker server integration in such a way that it gets cleaned up automatically.

Definition of Done

• CodeChekcer server is cleaned up automatically

[Szelethus]

Can you actually produce such as error? What if you interrupt the server test run?

[furtib]

Actually, no... strange.
I even tried an interrupt during the setup part of the test