* fix(conversion): serialize uuid.UUID payload values over gRPC
json_to_value only converted datetime and date objects to strings, so a
payload holding a uuid.UUID (at any depth) raised "Not supported json
value" with prefer_grpc=True, while the REST client and local mode both
store it as the canonical UUID string. This hit upsert, set_payload and
the gRPC uploader alike.
Route uuid.UUID through the same to_jsonable_python branch as datetime,
so both transports send the same value.
* fix: encode payload values under pydantic v1 the same way as REST
* test: wait for upload_collection in uuid payload congruence test
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Co-authored-by: George Panchuk <george.panchuk@qdrant.tech>
