Add a Crypto.bruteforce method

[postmodern]

Add a Crypto.bruteforce method which takes a wordlist and passes each password to the given block, which then tries to decrypt the String. The method should then test whether the decrypted String has entropy below 7.0 or contains a plaintext String.

Crypto.bruteforce(cipher_text, wordlist: 'AAAA'..'ZZZZ') do |password|
  cipher_text.aes256_decrypt(password: password)
end

Crypto.bruteforce(cipher_text, wordlist: Chars.ascii, matches: /^CNS/) do |key|
  cipher_text.xor(key)
end

The method should return multiple matches, and return both the password and the decrypted value:

[
  ["password123", "hello world"],
  ...,
  ["xjklfdjsklf", ".....hello....."]
]