function checkInputForSig(input, action) {
  const pSigs = extractPartialSigs(input);
  return pSigs.some(pSig =>
    signatureBlocksAction(pSig, bscript.signature.decode, action),
  );
}
Checks if an input contains a signature for a specific action.
@param input - The input to check.
@param action - The action to check for.
@returns A boolean indicating whether the input contains a signature for the specified action.