replace the custom Graphene mutation `RetrieveExactProducts` with a unified DRF implementation using `inline_serializer`. Updated GraphQL schema to resolve `retrieve_exact_products` query using a standardized approach.
This change improves consistency across DRF and GraphQL APIs, reduces duplicate logic, and centralizes request validations.
introduce `exact_list` action in `viewsets.py` to retrieve products by `uuid`, `slug`, or `sku` identifiers. Includes input validation and ratelimiting. Adds corresponding schema documentation and a GraphQL mutation for similar functionality.
Fixes: 1) Correct `lookup_field` to `uuid` in various viewsets; 2) Replace `type=str` with `OpenApiTypes.STR` in path parameters of multiple DRF endpoints; 3) Add missing import `iscoroutinefunction` and `markcoroutinefunction`.
Extra: 1) Refactor `__call__` method in `CamelCaseMiddleWare` to separate sync and async logic; 2) Enhance documentation schema responses with precise types in multiple DRF views.
