AccountId: `${ScopedChainId}:${string}`

à la CAIP-10

account_id: chain_id + ":" + account_address chain_id: [-a-z0-9]{3,8}:[-_a-zA-Z0-9]{1,32} (See [CAIP-2][]) account_address: [-.%a-zA-Z0-9]{1,128}