Network-Funded Account Onboarding

Renamed the account gift.vaulta, added halt and suspend permissions, set a 256 KiB default quota, added the creator application.

Added the enabled flag and its break-glass permission, set a quota floor, and stated the newaccount signer need not be the paying creator.

Named the account authorities, fixed the seed at 1,000,000,000 bytes, disclosed exhaustion, closed the open questions, repointed the pin.

Initial draft.