Add an external stablecoin to the approved list.
Must be [Config::ManagerOrigin].
Config::ManagerOrigin
asset_id
Error::AssetAlreadyApproved
Event::ExternalAssetAdded
Add an external stablecoin to the approved list.
Dispatch Origin
Must be [
Config::ManagerOrigin].Parameters
asset_id: The external stablecoin to addErrors
Error::AssetAlreadyApproved]: If the asset is already in the approved listEvents
Event::ExternalAssetAdded]: Emitted on successful addition