* Added backend class for SparseEncoder and also SentenceTransformersSparseTextEmbedder
* Added SentenceTransformersSparseDocumentEmbedder
* Created a separate _SentenceTransformersSparseEmbeddingBackendFactory and added tests
* Remove unused parameter
* Wrapped output into SparseEmbedding dataclass + fix tests
* Return correct SparseEmbedding, imports and tests
* fix fmt
* Style changes and fixes
* Added a test for embed function
* Added integration test and fixed some other tests
* Add lint fixes
* Fixed positional arguments
* fix types, simplify and more
* fix
* token fixes
* pydocs, small model in test, cache improvement
* try 3.9 for docs
* better to pin click
* release note
* small fix
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Co-authored-by: anakin87 <stefanofiorucci@gmail.com>
