Update on "[5.1/ N] set_option/get_option API with {backend_name, backend options} only"

This PR only expose the set_option/get_option API via the pair {backend_name, backend_options}, without necessarily backend options map. The backend options map and it's corresponding API will be exposed to another PR

Reference PR in #11758 which exposes the set_option/get_option with backendoptions map too

Differential Revision: [D77190316](https://our.internmc.facebook.com/intern/diff/D77190316/)

[ghstack-poisoned]

Author: cccclai