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/ccaosdb.h

@@ -325,7 +325,11 @@ int caosdb_entity_entity_get_id(caosdb_entity_entity *entity, char **out);
 int caosdb_entity_entity_get_role(caosdb_entity_entity *entity, char **out);
 int caosdb_entity_entity_get_name(caosdb_entity_entity *entity, char **out);
 int caosdb_entity_entity_get_description(caosdb_entity_entity *entity, char **out);
-int caosdb_entity_entity_get_datatype(caosdb_entity_entity *entity, char **out);
+/**
+ * Get the name of the entity's datatype, whether it is a reference, and whether it is a list.
+ */
+int caosdb_entity_entity_get_datatype(caosdb_entity_entity *entity, char **name, bool *is_ref,
+                                      bool *is_list);
 int caosdb_entity_entity_get_unit(caosdb_entity_entity *entity, char **out);
 
 int caosdb_entity_entity_get_int_value(caosdb_entity_entity *entity, long *out);
@@ -363,7 +367,11 @@ int caosdb_entity_property_get_id(caosdb_entity_property *property, char **out);
 int caosdb_entity_property_get_name(caosdb_entity_property *property, char **out);
 int caosdb_entity_property_get_description(caosdb_entity_property *property, char **out);
 int caosdb_entity_property_get_importance(caosdb_entity_property *property, char **out);
-int caosdb_entity_property_get_datatype(caosdb_entity_property *property, char **out);
+/**
+ * Get the name of the property's datatype, whether it is a reference, and whether it is a list.
+ */
+int caosdb_entity_property_get_datatype(caosdb_entity_property *property, char **name, bool *is_ref,
+                                        bool *is_list);
 int caosdb_entity_property_get_unit(caosdb_entity_property *property, char **out);
 
 int caosdb_entity_property_get_int_value(caosdb_entity_property *property, long *out);
@@ -399,7 +407,11 @@ int caosdb_entity_delete_parent(caosdb_entity_parent *out);
 int caosdb_entity_entity_set_role(caosdb_entity_entity *entity, const char *role);
 int caosdb_entity_entity_set_name(caosdb_entity_entity *entity, const char *name);
 int caosdb_entity_entity_set_description(caosdb_entity_entity *entity, const char *description);
-int caosdb_entity_entity_set_datatype(caosdb_entity_entity *entity, const char *datatype);
+/**
+ * Set the entity's datatype by name, and whether it is a reference or a list.
+ */
+int caosdb_entity_entity_set_datatype(caosdb_entity_entity *entity, const char *datatype,
+                                      const bool is_ref, const bool is_list);
 int caosdb_entity_entity_set_unit(caosdb_entity_entity *entity, const char *unit);
 // TODO(fspreck) replace by more specific setters
 int caosdb_entity_entity_set_int_value(caosdb_entity_entity *entity, const long value);
@@ -423,7 +435,11 @@ int caosdb_entity_entity_remove_property(caosdb_entity_entity *entity, int index
 
 int caosdb_entity_property_set_id(caosdb_entity_property *property, const char *id);
 int caosdb_entity_property_set_name(caosdb_entity_property *property, const char *name);
-int caosdb_entity_property_set_datatype(caosdb_entity_property *property, const char *datatype);
+/**
+ * Set the property's datatype by name, and whether it is a reference or a list.
+ */
+int caosdb_entity_property_set_datatype(caosdb_entity_property *property, const char *datatype,
+                                        const bool is_ref, const bool is_list);
 int caosdb_entity_property_set_importance(caosdb_entity_property *property, const char *importance);
 int caosdb_entity_property_set_unit(caosdb_entity_property *property, const char *unit);