Add ChaCha20-Poly1305 Support for OpenSSH Keys

[exceptionfactory]

This pull request adds support for the [email protected] cipher when decrypting OpenSSH Private Keys.

The implementation required adjusting the ChachaPolyCipher.update() method to accept an input offset of 0, indicating no Additional Authenticated Data included with the encrypted bytes.

[codecov-commenter]

Codecov Report

Merging #904 (32b4e12) into master (3b67d2b) will decrease coverage by 0.02%.
The diff coverage is 92.85%.

@@             Coverage Diff              @@
##             master     #904      +/-   ##
============================================
- Coverage     68.45%   68.44%   -0.02%     
+ Complexity     1402     1400       -2     
============================================
  Files           207      207              
  Lines          7475     7478       +3     
  Branches        630      631       +1     
============================================
+ Hits           5117     5118       +1     
- Misses         2023     2024       +1     
- Partials        335      336       +1     

Files	Coverage Δ
...sshj/userauth/keyprovider/OpenSSHKeyV1KeyFile.java	86.45% <100.00%> (+0.07%)	⬆️
...ynomus/sshj/transport/cipher/ChachaPolyCipher.java	77.94% <91.66%> (+0.66%)	⬆️

... and 8 files with indirect coverage changes