Add CPU instruction limiter

[craigthomas]

This PR adds a limit on the number of instructions that can be executed per second, instead of implementing an instruction delay. This PR closes #58

[codecov]

Codecov Report

Attention: Patch coverage is 66.66667% with 7 lines in your changes missing coverage. Please review.

Project coverage is 73.63%. Comparing base (796038d) to head (e3f0a4d).

Files with missing lines	Patch %	Lines
...ava/emulator/components/CentralProcessingUnit.java	77.77%	3 Missing and 1 partial ⚠️
...thomas/chip8java/emulator/components/Emulator.java	0.00%	2 Missing ⚠️
...aigthomas/chip8java/emulator/runner/Arguments.java	0.00%	1 Missing ⚠️

Additional details and impacted files

@@             Coverage Diff              @@
##               main      #60      +/-   ##
============================================
+ Coverage     73.33%   73.63%   +0.30%     
  Complexity      286      286              
============================================
  Files            12       12              
  Lines          1069     1066       -3     
  Branches        135      135              
============================================
+ Hits            784      785       +1     
+ Misses          264      259       -5     
- Partials         21       22       +1     

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