F grpc f value and unit

Summary

Fixes for #169 (closed) and caosdb-cpplib#10 (closed)

• The values are returned in their "native" representation, e.g. as integer, double or boolean.
• The units are inherited correctly and returned correctly.

Focus

• The units have not been returned because the Entity.hasUnit method doesn't do what we would expect it to do (for several reasons, mainly because the serialization of the unit for the REST-API works differently.)
• Also, I noticed that the units are not inherited as expected because of a missing "inheritance" flag (which is not part of the GRPC-API yet).
• The values needed to be parsed prior to the serialization with parseValue() in order to output them in their "native" representation.

Test Environment

Integration tests in caosdb-cppinttest!13 (merged) should do it.

Check List for the Author

Please, prepare your MR for a review. Be sure to write a summary and a focus and create gitlab comments for the reviewer. They should guide the reviewer through the changes, explain your changes and also point out open questions. For further good practices have a look at our review guidelines

• All automated tests pass
• Reference related Issues
• Up-to-date CHANGELOG.md
• 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 specifications? Are they satisfied?

For further good practices have a look at our review guidelines.