BTC Wallets: OneKey Signet switch network

[gbarkhatov]

window.$onekey.btcwallet.switchNetwork does not support "signet" network at the moment (or might support it in the latest update).
We need to apply this logic before we're getting the address

Reference: #102 (comment)

    // switch (this.networkEnv) {
    //   case Network.MAINNET:
    //     await this.bitcoinNetworkProvider.switchNetwork(
    //       INTERNAL_NETWORK_NAMES.mainnet,
    //     );
    //     break;
    //   case Network.TESTNET:
    //     await this.bitcoinNetworkProvider.switchNetwork(
    //       INTERNAL_NETWORK_NAMES.testnet,
    //     );
    //     break;
    //   case Network.SIGNET:
    //     await this.bitcoinNetworkProvider.switchNetwork(
    //       INTERNAL_NETWORK_NAMES.signet,
    //     );
    //     break;
    //   default:
    //     throw new Error("Unsupported network");
    // }