Practice has shown that environment-induced error messages may
appear during test runs. For example, incorrect resolver settings
may cause name resolution warnings or errors. These are unrelated
to the test itself.
This patch enables tests that are otherwise unaffected by the faillures
to continue and provide "pass" test result.
see also https://github.com/rsyslog/rsyslog/issues/4619
Also now permit interactivly running tests without explicitly setting
$srcdir. This now works if we are inside ./tests and fails, as before,
when we are in a different directory.
Detected by shellcheck via CodeFactor.io
changes some of the test commands to use bash functions
includes some small bug fixes to tests where bugs were
previously not seen due to different plumbing.
This will mark them as SKIPPED instead of FAILED, making it at least
in theory possible to get 0 FAILED tests even when running as an
unprivileged user.
