[WIP] Hybrid Search

[vicilliar]

• What kind of change does this PR introduce? (Bug fix, feature, docs update, ...) Feature

• What is the current behavior? (You can also link to an open issue here) Only tensor and lexical are the allowed search methods.

• What is the new behavior (if this is a feature change)? New search method: HYBRID introduced with hybrid_parameters parameter.

Hybrid parameters has the following parameters

    retrieval_method: str
    ranking_method: str
    alpha: float
    searchable_attributes_lexical: List[str]
    searchable_attributes_tensor: List[str]

Possible retrieval methods are: ["disjunction", "tensor", "lexical"]. The disjunction method combines both tensor and lexical.

Possible ranking methods are: ["rrf", "normalize_linear", "tensor", "lexical"]. Therrfandnormalize_linear` methods combine both tensor and lexical.

• Does this PR introduce a breaking change? (What changes might users need to make in their application due to this PR?) No

• Have unit tests been run against this PR? (Has there also been any additional testing?) In progress

• Related Python client changes (link commit/PR here) In progress

• Related documentation changes (link commit/PR here)

• Other information:

• Please check if the PR fulfills these requirements

• [ ] The commit message follows our guidelines

• [ ] Tests for the changes have been added (for bug fixes/features)

• [ ] Docs have been added / updated (for bug fixes / features)