Add SQLite Hybrid Search and BM25 for local vector search

[franciscojavierarceo]

Is your feature request related to a problem? Please describe.
See this example: https://github.com/liamca/sqlite-hybrid-search/tree/main and the sqlite docs: https://www.sqlite.org/fts5.html

This should be complemented with the SQLite-vec implementation.

Describe the solution you'd like

document_embeddings = FeatureView(
    name="embedded_documents",
    entities=[item, author],
    schema=[
        Field(
            name="vector",
            dtype=Array(Float32),
            # Look how easy it is to enable RAG!
            vector_index=True,
            vector_search_metric="COSINE",
        ),
        Field(name="item_id", dtype=Int64),
        Field(name="author_id", dtype=String),
        Field(name="created_timestamp", dtype=UnixTimestamp),
        Field(name="sentence_chunks", dtype=String),
        Field(name="event_timestamp", dtype=UnixTimestamp),
    ],
    source=rag_documents_source,
    ttl=timedelta(hours=24),
)

Somewhere in the FeatureView we should allow the search to be declared explicitly.

Describe alternatives you've considered
TBD

Additional context
Add any other context or screenshots about the feature request here.