Add custom Pezkuwi networks to SS58 address prefix dropdown since they
are not in the upstream @substrate/ss58-registry package:
- Pezkuwi Relay Chain (prefix: 0)
- Dicle Relay Chain (prefix: 2)
- Zagros Testnet (prefix: 42)
- PezkuwiChain Development (prefix: 42)
Also filter out polkadot/kusama from the list as they are replaced
by pezkuwi/dicle in this project.
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
