Add HuggingFaceHubBucketFSModelTransfer with save_pretrained

[MarleneKress79789]

Background:

• Currently, we use from_pretrained with the cache_dir option to load the model and upload the cache directory to the BucketFS
• The current approach in general works, but seems to check each time online if the model exists, we have access and we have the newest version
• This is not possible in some deployments
• To solve this issue, we could follow the following example using save_pretrained which stores the model into a directory which we then could upload
• We can then load the model with from_pretrained from a local path
• For this we first need a download function which uses save_pretrained

Acceptance Criteria

### Tasks
- [x] Add a duplicate of the existing [model download](https://github.com/exasol/transformers-extension/blob/1321af15f1cf0e9ac68ca12c02a3d6e4318a2cb1/exasol_transformers_extension/udfs/models/model_downloader_udf.py) which uses the save_pretrained function and
- [x] add tests for the new download functionality

[MarleneKress79789]

planning and splitting ticket: 0.5 pd