Refactor Pipeparts

.gitlab-ci.yml

gstlal/pytest.ini

gstlal/python/Makefile.am

gstlal/python/gsttools.py

gstlal/python/pipeparts/Makefile.am

gstlal/python/pipeparts/__init__.py

gstlal/python/pipeparts/encode.py

gstlal/python/pipeparts/filters.py

gstlal/python/pipeparts/mux.py

gstlal/python/pipeparts/pipedot.py

gstlal/python/pipeparts/pipetools.py

gstlal/python/pipeparts/plot.py

gstlal/python/pipeparts/sink.py

gstlal/python/pipeparts/source.py

gstlal/python/pipeparts/transform.py

gstlal/python/pipeparts/trigger.py

gstlal/python/utilities/testtools.py

gstlal/share/conda/set_env.sh

gstlal/tests/tests_pytest/pipeparts/test_encode.py

gstlal/tests/tests_pytest/pipeparts/test_filters.py