Update base for Update on "[3/N] Add get_option/set_option function in backend interface"

Add update function in backend interface class. The update function will receive the backend options from dispatched by the ET runtime.

ET runtime's logic: loop over each backend and it's corresponding backend options, dispatch the backend options to the corresponding backend

Next step, will add update API in the method and then module
exported-using-ghexport

Differential Revision: [D75919242](https://our.internmc.facebook.com/intern/diff/D75919242/)

Differential Revision: [D75919242](https://our.internmc.facebook.com/intern/diff/D75919242)

[ghstack-poisoned]

Author: cccclai