Add custom error type for broadcasting

[catrias]

Stargate client broadcastTx method only provides text on error.

throw new Error(
  `Broadcasting transaction failed with code ${broadcasted.code} (codespace: ${broadcasted.codeSpace}). Log: ${broadcasted.log}`,
);

It would be useful to use some custom error class to include the code like

export class BroadcastTxError extends Error {
  constructor(public readonly code: number, message?: string) {
    super(message);
  }
}

throw new BroadcastTxError(
  broadcasted.code
  `Broadcasting transaction failed with code ${broadcasted.code} (codespace: ${broadcasted.codeSpace}). Log: ${broadcasted.log}`,
);

[webmaster128]

Good idea, thanks. See #1235

[webmaster128]

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