CORE-341: Make AddressScheme an enum and axe the `name` property.
CORE-341: Make AddressScheme an enum and axe the `name` property.

breadwallet/breadwallet-core,breadwallet/breadwallet-core,breadwallet/breadwallet-core,breadwallet/breadwallet-core,breadwallet/breadwallet-core,breadwallet/breadwallet-core