Pass (sub)walletId in Mnemonic provider

[midas-myth]

hello thank you for your library

blueprint/src/network/send/MnemonicProvider.ts

Line 60 in 6b103e1

export class MnemonicProvider implements SendProvider {

WalletContractV3R2 accepts walletId, but there is no way to pass it right now. As only mnemonic and wallet version are being read from environment. We could add another env variable and pass it through.

export class MnemonicProvider implements SendProvider {
    #wallet: OpenedContract<WalletInstance>;
    #secretKey: Buffer;
    #client: TonClient4 | TonClient;
    #ui: UIProvider;

    constructor(params: {
        version: WalletVersion;
        workchain?: number;
        secretKey: Buffer;
        client: TonClient4 | TonClient;
        ui: UIProvider;
        // here sould bw walletId
    }) {
        if (!(params.version in wallets)) {
            throw new Error(`Unknown wallet version ${params.version}`);
        }

        const kp = keyPairFromSecretKey(params.secretKey);
        this.#client = params.client;
        this.#wallet = openContract<WalletInstance>(
            wallets[params.version].create({
                workchain: params.workchain ?? 0,
                publicKey: kp.publicKey,
                // here should be walletId
            }),
            (params) => this.#client.provider(params.address, params.init),
        );
        this.#secretKey = kp.secretKey;
        this.#ui = params.ui;
    }
    // ...
}

If would like i could provide a pr adding env var parsing. seems it might solve