SSDM-13524: Added handling of array-type properties to pybis. Minor code refactor.

api-openbis-python3-pybis/src/python/pybis/definitions.py

api-openbis-python3-pybis/src/python/pybis/entity_type.py

api-openbis-python3-pybis/src/python/pybis/experiment.py

api-openbis-python3-pybis/src/python/pybis/openbis_object.py

api-openbis-python3-pybis/src/python/pybis/property.py

...is-python3-pybis/src/python/pybis/property_reformatter.py

api-openbis-python3-pybis/src/python/pybis/pybis.py

api-openbis-python3-pybis/src/python/pybis/sample.py

api-openbis-python3-pybis/src/python/pybis/utils.py