ADFGX Cipher python implementation

[itspyguru]

1> Implement a ADFGX Cipher encryption and decryption method and wrap it inside a class ADFGXCipher
2> save it to adfgx_cipher.py
3> put the file inside decrypto/src folder
4> submit a PR.

Sample implementation : https://github.com/pyGuru123/Decrypto/blob/main/decrypto/src/binary_cipher.py
strictly follow above implementation and PEP8 Guidelines

[murugan-k-0204]

I want to work on this. Assign me

[itspyguru]

go for it