T3060
Per the updated alias spec, alias registration txs will have the following format
`6a` - OP_RETURN
`04` - 4 bytes pushdata
`2e786563` - alias protocol identifier (".xec")
`**` - n bytes pushdata, 1 +`01` - alias.length, in hex, e.g. '05' for a 4-byte alias registration protocol version number pushdata
`01****``00` - alias protocol version number + alias in hex, e.g. `0174657374` for the alias 'test'
`15`**` - 21 bytes of pushdata for address (assumes 20 byte payload and 1 , alias.length, in hex, e.g. '04' for a 4-byte for p2sh or p2pkh identifier.alias registration, could be some other constantsa value between `0x01` and `0x15`
`********` - n bytes, not necessarily hex byte for `21`)alias in hex
`15` - 21 bytes of pushdata for address and address version byte
`00` or `08` - marks address as p2pkh or p2sh
`<hash>` - address payload
A new function `generateAliasOpReturnScript` is added to create an OP_RETURN script matching this spec. Unit tests are added for sample registrations to p2pkh and p2sh addresses.