Upgrade basic AES block cipher

[mborland]

Instead of putting the encryption modes into one giant class like last time we are going to separate them out responsibly.

Closes: #244

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 99.94%. Comparing base (f17fe1d) to head (d6a2ef2).
Report is 18 commits behind head on develop.

Additional details and impacted files

@@            Coverage Diff            @@
##           develop     #254    +/-   ##
=========================================
  Coverage    99.94%   99.94%            
=========================================
  Files           96       98     +2     
  Lines         3711     3926   +215     
=========================================
+ Hits          3709     3924   +215     
  Misses           2        2            

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