tests: fix some broken logging

tests: fix some broken logging

- make sure we close and remove all handlers for named logs on each reuse.
- test module level exec.log no longer truncated to last test case output
- cleanup the log names, and make sure they are present in all exec logs
- keep separate exec logs for each pytest worker when running in distributed mode
- disabled code due to CI infra can't handle it: add per test case exec logs

Signed-off-by: Christian Hopps <chopps@labn.net>