[typing] stem_dictionary missing from CollectionFieldSchema

[valesken]

The stem_dictionary field is supported when creating a Collection, but the field is missing from the CollectionFieldSchema: https://github.com/typesense/typesense-python/blob/master/src/typesense/types/collection.py#L52

I did notice tests that assert the behavior functions as expected, but it would be good to get the types to match:

typesense-python/tests/collections_test.py

Line 202 in 9777059

"stem_dictionary": "",