feat(api): add project residency configuration and cost quantity units (#3726)

## Summary

Adds optional `residency` support to synchronous and asynchronous Admin
Organization project creation, with typed residency configuration
values, and exposes `residency` on returned Project models. Marks
`geography` as deprecated for project creation while retaining it for
backward compatibility. Adds optional `quantity_unit` fields to
organization usage cost result models across supported usage response
types.

Project responses and project-creation inputs now reuse a shared
residency model. Usage cost responses reuse a shared quantity-unit
model, with unknown unit values and optional/null fields preserved.

Co-authored-by: apcha-oai <228803254+apcha-oai@users.noreply.github.com>