style: get rid of unnecessary type conversions

examples: 

```py
# is string already!  why the cast? 
            if type(type_) == str:
                type_to_parse = str(type_)
```

```py
# is in list already! why the cast? 
                    if results.get('array_type', None) in self._SORTED_CONTAINERS_TYPES:
                        mapped_array_type = self._SORTED_CONTAINERS_TYPES.get(str(results.get("array_type")))
```