Adapt test data to attribute name change from MIXED-CONTENT to VALUE.
Adapted test data to JSON format change for attribute MIXED-CONTENT
renamed to VALUE and MOTCLE element structure now containing objects
instead of primitives.
Revert broken MIXED-CONTENT tag renaming and keep MOTCLE structure
change.
Effectively replace MIXED-CONTENT attribute name by VALUE.
Perform basic ' ' to '+' encoding on GET query parameter. Might need to
be extended.