ENH: Add datatypes and value classes to Extern C interface

Summary

See https://gitlab.indiscale.com/caosdb/customers/lfpb/management/-/issues/420. Adapts the

Focus

The single get_value functions are now split up into get_<datatype>_value, get_value_list_length, and get_<datatype>_list_value_at functions. Also, importances, roles, and datatypes are now cast from string to enums and back for getting and setting. In the case of datatypes, two additional Booleans for is_reference and is_list.

In addition, the way memory si allocated in case of char pointers has been fixed.

Test Environment

Unit tests and integration tests should be sufficient. Integration testing with deploy in f-grpc and server in f-grpc-f-consolidation, as usual.

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.

include/caosdb/value.h

@@ -132,6 +132,8 @@ public:
   }
 
   LIST_VALUE_CONSTRUCTOR(int64_t, set_integer_value)
+  LIST_VALUE_CONSTRUCTOR(double, set_double_value)
+  LIST_VALUE_CONSTRUCTOR(bool, set_boolean_value)
 
   [[nodiscard]] inline auto IsNull() -> bool {
     return this->wrapped->value_case() == ValueCase::VALUE_NOT_SET;