ci/lava: Add a simple Structural Logger into submitter

ci/lava: Add a simple Structural Logger into submitter

Refactor some pieces of the submitter to improve the clarity of the
functions and create a simple dictionary with aggregated data from the
submitter execution which will be dumped to a file when the script
exits.

Add support for the AutoSaveDict based structured logger as well, which
will come in a follow-up commit.

Signed-off-by: Guilherme Gallo <guilherme.gallo@collabora.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/22500>