feat: add Bitcoin support

[baptiste-marchand]

This PR add Bitcoin support by updating types

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Note

Adds a Bitcoin bip122 RPC scope with UTXO/PSBT/signing/transfer methods and registers it in the default RPC API.

• Types:
  • bip122 scope: Introduces Bip122Rpc with Bitcoin methods: signMessage, sendTransfer, signPsbt (with fill/broadcast options and optional feeRate), fillPsbt, broadcastPsbt, computeFee, and getUtxo.
  • UTXO model: Adds Utxo type (outpoint, value, derivationIndex, scriptPubkey/scriptPubkeyHex, optional address).
• API Registration:
  • Adds bip122: Bip122Rpc to DefaultRpcApi in src/types/scopes/index.ts.

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