Add function to traverse json tree and free all memory allocations

include/json_entities/json_entities.h

@@ -65,6 +65,7 @@ struct json_collection {
 };
 
 void print_json(const jentity_t *entity, u32 indent);
+void free_json(jentity_t **entity);
 jcoll_t *get_collection_from_entity(const jentity_t *entity);
 jentity_t *create_new_single_entity(const jval_t value, jentity_t *parent);
 jentity_t *create_new_pair_entity(dstr_t *key, const jval_t value,