Adding support for SevenZ password encryption

👉🏼 The purpose is to provide password based encryption for 7z compression in the same way of decryption already supported, so go forward of one know limitation

☝️In this way, I would like to submit my contribution based on the existing implementation of decryption and the C++ implementation of 7z 

✅ I added one unit test
 
I prepared a Pull Request on GitHub