[Subtask] Fileset connector for PyTorch

### Describe the subtask

Develop a PyTorch connector to load the data in a Gravitino Fileset. We can use this article as a reference:

https://docs.snowflake.com/en/developer-guide/snowpark-ml/snowpark-ml-framework-connectors

### Parent issue

#2113

Start by reading parent issue #2113 and the linked Snowflake connector article to understand the expected connector behavior. Define the PyTorch connector's scope around loading data from a Gravitino Fileset; completion means that Fileset data can be loaded through PyTorch.

Written by the indexing model from the issue text.