runner: Use 'abort' as result if a test caused an abort

If a test caused an abort condition to trigger, a pseudoresult
"igt@runner@aborted" would be generated, detailing which test caused
the condition. That was implemented in a simpler world where there
were no dynamic subtests and CI systems (i915-CI in particular) didn't
have much test resuming happening.

The generated pseudoresult was completely unable to point to a
particular dynamic subtest if the executed subtest had any, and there
could inherently be only one of them. When combined with the fact that
the pseudoresult doesn't have logs that could be used to automatically
point to particular bug reports, that made results filtering by
CIBugLog difficult.

With socket communications it's easier to inject information "in
between" test's logs and result overriding is designed into the
system. Thus, when using socket communications, this patch series will
make the abort-condition-causing test's result 'abort' instead of
using that pseudoresult.

The flow becomes a little bit messier with monitor_output() gaining
more and more out-parameters but those can be cleaned later.

v2: Handle abort conditions between dynamic subtests

Signed-off-by: Petri Latvala <petri.latvala@intel.com>
Cc: Arkadiusz Hiler <arek@hiler.eu>
Cc: Kamil Konieczny <kamil.konieczny@linux.intel.com>
Acked-by: Kamil Konieczny <kamil.konieczny@linux.intel.com>