72 flatten 4_sign_off.ttl files

[EttoreM]

This PR addresses #72.

The work done for this PR consists of flattening the ttl files pertaining to the 4_sign_off ruleset.
In addition, the SHACL shapes were minimally updated by adding sh:name where it was missing. This is required for the existing tests to evaluate the shapes correctly and pass consistently.

Currently there are 4 tests failing

FAILED tests/integration/profiles/five-safes-crate/test_5src_1_root_data_entity_metadata.py::test_5src_root_data_entity_source_organization_not_organization - AssertionError: The expected requirement "RootDataEntity" was not found in the failed requirements
FAILED tests/integration/profiles/five-safes-crate/test_5src_2_requesting_agent.py::test_createaction_does_not_have_agent - AssertionError: The expected requirement "CreateAction" was not found in the failed requirements
FAILED tests/integration/profiles/five-safes-crate/test_5src_2_requesting_agent.py::test_createaction_agent_is_not_person - AssertionError: The expected requirement "CreateAction" was not found in the failed requirements
FAILED tests/integration/profiles/five-safes-crate/test_5src_2_requesting_agent.py::test_agent_affiliation_not_organization - AssertionError: The expected requirement "CreateAction" was not found in the failed requirements

None of these is directly related to the ruleset in question.