[Ticket]: List decided augmentation requests

## Type

Feature

## Summary

Add a cursor-paginated listDecidedAugmentationRequests returning decision, decider, and decided-at. The console currently fabricates its Decided list from the pending-only feed, which is wrong by construction; the fabricated surface is being removed and cannot return until this endpoint exists.

## Intent

Console UI/UX revamp epic: https://github.com/ADORSYS-GIS/converse-frontends/issues/368 — the console cuts every surface that fakes missing backend data; this ticket is the backend contract needed to restore the surface honestly.

## Acceptance Criteria

- Contract available over the authz-rpc / usage query path the console consumes.
- Console follow-up can render real values with no hardcoded nulls.

_Source of truth: https://github.com/ADORSYS-GIS/converse-frontends/issues/368_