feat: add accountInfo request to retrieve account details

[Kiranchaudhary537]

I’ve submitted a PR to introduce a new method, getAddressInfo, which retrieves a wallet’s account data (e.g., publicKey, address, and optional addressType).

Why this change?
While using the package for wallet interactions (signing, connecting, etc.), I needed access to the user’s public key for building unsigned PSBTs. Since the current implementation didn’t provide this data, I added it to the accountInfo method while ensuring existing integrations remain unaffected.

Changes made:

1. Added getAddressInfo(client) request which take no params and return BtcAccount[].

ex.

import { getAddressInfo } from '@bigmi/core';  
const accountInfo = await getAddressInfo(client);

[chybisov]

We had a discussion and agreed for the next structure of BtcAccount type returned from getAccount.

{
      address: string
      addressType: 'p2tr' | 'p2wpkh' | 'p2sh' | 'p2pkh'
      purpose: 'payment' | 'ordinals'
      publicKey: string
      accounts: readonly BtcAccount[]
      chain: chain | undefined
      chainId: number
      connector: Connector
      isConnected: true
      isConnecting: false
      isDisconnected: false
      isReconnecting: false
      status: 'connected'
    }