[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: https://github.com/typesense/typesense-python/blob/9777059d77dfd15a554c9584200050c6f1783f1e/tests/collections_test.py#L202