[v1.11.0] Support facet distribution for federated search

[brunoocasali]

Following this central issue

Explanation of the feature

Related issue in the engine: meilisearch/meilisearch#4932

• Request facet distributions and facet stats in your federated search, by using federation.facetsByIndex in the POST POST /multi-search route.
• Merge the returned facets in a single facet distribution and stats that is global to the entire request, by using federation.mergeFacets in the POST POST /multi-search route.

[ellnix]

I don't think this needs any action, since the multi search method accepts a Dict of options:

    def multi_search(
        self, queries: Sequence[Mapping[str, Any]], federation: Optional[Dict[str, Any]] = None
    ) -> Dict[str, List[Dict[str, Any]]]:

meilisearch-python/meilisearch/client.py

Line 222 in a43baec

def multi_search(