post
https://apis.kentro.live/store/v1/addresses.save
Adds an address (no id; an optional createId of your own makes the add idempotent) or changes one (id with its expectedVersion). isDefault: true makes it the default. type is shipping, billing, mailing or general.
Who may call it: A signed-in buyer (X-Storefront-Buyer); without one the answer is 401 UNAUTHORIZED.
