F merge missing list datatype

Summary

For #151 (closed). Does not fix the actual problem because this is a CloseWon't Fix (or has to be fixed in the crawler) but raises a better error message instead.

Focus

Check that the correct error message is shown.

Test Environment

Unit tests should be sufficient.

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CHANGELOG.md

@@ -24,6 +24,10 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ### Fixed ###
 
+* [#82](https://gitlab.com/caosdb/caosdb-pylib/-/issues/82) Merging an entity
+  with properties with missing datatype leads to Exception - list datatypes are
+  now inferred from scalar datatype in force merges.
+
 ### Security ###
 
 ### Documentation ###