decrypt method
The decrypt() method of the SubtleCrypto interface decrypts some
encrypted data.
It takes as arguments a  to decrypt with, some optional extra parameters,
and the data to decrypt (also known as "ciphertext").
It returns a Promise which will be fulfilled with the decrypted data
(also known as "plaintext").
Implementation
external JSPromise<JSAny?> decrypt(
  AlgorithmIdentifier algorithm,
  CryptoKey key,
  BufferSource data,
);