Add flag and cuid getters to Entity

Summary

Added new protected property getters to Entity.
Needed for caosdb-advanced-user-tools!126 (merged)

Test Environment

No testing should be necessary, access should be read-only - does the dict always have strings as values?

Check List for the Author

• All automated tests pass
• Reference related issues
• Up-to-date CHANGELOG.md
• Appropriate user and developer documentation (or not necessary)
• Annotations in code (Gitlab comments)

Check List for the Reviewer

• I understand the intent of this MR
• All automated tests pass
• Up-to-date CHANGELOG.md (or not necessary)
• Appropriate user and developer documentation (or not necessary)
• In-code documentation and comments are up-to-date.

unittests/test_container.py

@@ -70,7 +70,8 @@ def test_get_property_values():
                                           )
     assert len(table) == 2
     house_row = table[0]
-    assert house_row == (house.name, 40.2, "ft", window.id, None, None, None, 20.5, 20.5, "m", owner.name)
+    assert house_row == (house.name, 40.2, "ft", window.id, None, None, None, 20.5, 20.5, "m",
+                         owner.name)
 
     owner_row = table[1]
     assert owner_row == (owner.name, None, None, None, None, None, None, None, None, None, None)
@@ -200,11 +201,12 @@ def test_container_slicing():
     with pytest.raises(TypeError):
         cont[[0, 2, 3]]
 
+
 def test_container_filter():
     # this is a very rudimentary test since filter is based on _filter_entity_list which is tested
     # separately
     cont = db.Container()
     cont.extend([db.Record(name=f"TestRec{ii+1}") for ii in range(5)])
     recs = cont.filter(name="TestRec2")
-    assert len(recs)==1
-    recs[0].name =="TestRec2"
+    assert len(recs) == 1
+    recs[0].name == "TestRec2"