message: fix(bitgo): no `Buffer` support in browsers
  Instead of converting `BN` to `Buffer` eagerly,
  just make it another case that we can return, and let
  the code outside use it directly as they see fit.
  Ticket:
diff: @@ -567,7 +567,7 @@ export function hasSignature(txData: TxData): boolean {
  );
  }
  -type RecursiveBufferOrString = string | Buffer | RecursiveBufferOrString[];
  +type RecursiveBufferOrString = string | Buffer | BN | RecursiveBufferOrString[];
  /**
  * Get the raw data decoded for some types
  @@ -579,7 +579,7 @@ type RecursiveBufferOrString = string | Buffer | RecursiveBufferOrString[];
  export function getRawDecoded(types: string[], serializedArgs: Buffer): RecursiveBufferOrString[] {
  function normalize(v: unknown, i: number): unknown {
  if (BN.isBN(v)) {
  - return v.toBuffer();
  + return v;
  } else if (typeof v === 'string' || Buffer.isBuffer(v)) {
  return v;
  } else if (Array.isArray(v)) {
  