Fix migrate-keyring CLI to include address reverse-lookup entries

[metalarm10]

Description

QA reported: After selective key migration (e.g. txd keys migrate-keyring alice), the .info entry (alice.info) was migrated successfully. Users could look up keys by name (--from alice). But lookups by bech32 address (--from testcore1k343...) failed with "key not found".

This broke:

• Group proposal submission (proposers field uses bech32 addresses)
• Transactions with --from <address> flag

This PR fixes the issue: After migrating each .info entry, unmarshal the hex address, then migrate the corresponding <hex>.address entry as well.

Verified on coreum-testnet-1: key migration, address lookup, bank send with --from <address>, and group proposal submission tests passed.

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