fix: Make bech32 encoding network-aware

[scarmuega]

fixes #34

[mark-stopka]

Works as expected:

markstopka@mark-zenbook-s:~/Work/github.com/TxPipe/oura> ./target/debug/oura watch relays-new.cardano-testnet.iohkdev.io:3001 --bearer tcp --magic testnet | grep test
BLOCK:3269523 █ TX:00 █ UTXO   { to: addr_test1qzqy40s98kan50rljxpcgsnl9xesxsdpndzw430zmlad8rs368cnk3l9yrr5vmgw3hvg3hr6xgujvxa4zw3nwupeugkquspqlq, amount: 5000000 }
BLOCK:3269523 █ TX:00 █ UTXO   { to: addr_test1qpc6srdq6jjt6eetstw6t4elmypvepa6ykxcps3dvvv4fr5ca6s0m36w9nlk7ntwdhvhxeyz9u4lngn97fcv4ykjqc2sk4hrgy, amount: 178351064 }
BLOCK:3269523 █ TX:01 █ UTXO   { to: addr_test1wphyve8r76kvfr5yn6k0fcmq0mn2uf6c6mvtsrafmr7awcg0vnzpg, amount: 4000000 }
BLOCK:3269523 █ TX:01 █ UTXO   { to: addr_test1qpm970xdu8wk45uawumaqwaz5s0rs7up9lwsxfdqzhlce6mv7pq2ky2rls2k6sf4uwldc2xdjjtx5lyy446pm25u6c9szl45ut, amount: 449695296 }
^C
markstopka@mark-zenbook-s:~/Work/github.com/TxPipe/oura>