Expanded basic search (#4517)

* initial working version

* ranking profile

* modification for keyword/instruction retrieval

* mypy fixes

* EL comments

* added env var (True for now)

* flipped default to False

* mypy & final EL/CW comments + import issue

backend/onyx/tools/models.py

@@ -11,6 +11,7 @@ from onyx.configs.constants import DocumentSource
 from onyx.context.search.enums import SearchType
 from onyx.context.search.models import IndexFilters
 from onyx.context.search.models import InferenceSection
+from onyx.context.search.models import QueryExpansions
 from shared_configs.model_server_models import Embedding
 
 
@@ -79,6 +80,7 @@ class SearchToolOverrideKwargs(BaseModel):
     )
     document_sources: list[DocumentSource] | None = None
     time_cutoff: datetime | None = None
+    expanded_queries: QueryExpansions | None = None
 
     class Config:
         arbitrary_types_allowed = True