F fix compare entities branch2

Summary

This is a fix for #81 (closed) .

Focus

I added a statement analogous to existing statements for datatype and importance that compares the values of the entities.

Test Environment

I added a unit test in test_apiutils.py.

Issue #81 (closed) contains a script for testing it manually.

Check List for the Author

• All automated tests pass
• Reference related Issues
• Up-to-date CHANGELOG.md
• Add type hints in created/changed code
• Annotations in code (Gitlab comments)
  • Intent of new code
  • Problems with old code
  • Why this implementation?

Check List for the Reviewer

• I understand the intent of this MR
• All automated tests pass
• Up-to-date CHANGELOG.md
• The test environment setup works and the intended behavior is reproducible in the test environment
• In-code documentation and comments are up-to-date.
• Check: Are there spezifications? Are they satisfied?

src/caosdb/apiutils.py

@@ -639,6 +639,13 @@ def compare_entities(old_entity: Entity, new_entity: Entity):
                 newdiff["properties"][prop.name]["datatype"] = \
                     matching[0].datatype
 
+            if ((prop.value is not None and
+                    matching[0].value is not None) and
+                    (prop.value != matching[0].value)):
+                olddiff["properties"][prop.name]["value"] = prop.value
+                newdiff["properties"][prop.name]["value"] = \
+                    matching[0].value
+
             if (len(newdiff["properties"][prop.name]) == 0
                     and len(olddiff["properties"][prop.name]) == 0):
                 newdiff["properties"].pop(prop.name)