Choose a custom SS58 address format for DataHighway networks

References:

• ss58 network prefix questions paritytech/substrate#4927
• https://github.com/paritytech/substrate/blob/master/primitives/core/src/crypto.rs#L457
• https://github.com/paritytech/substrate/wiki/External-Address-Format-(SS58)#address-type
• https://github.com/paritytech/substrate/blob/master/primitives/core/src/crypto.rs#L435
• https://matrix.to/#/!XOxcnpiHXHhAjJfRFP:matrix.parity.io/$4d9RFalEYKLBuO7ES9H0j7QTKIVs0fTOU__FunkTtDQ?via=matrix.parity.io&via=matrix.org&via=web3.foundation
• https://github.com/w3f/PSPs