Create ast cppcheck for private and protected member function to have a leading underscore

[97gamjak]

Fixes #134

[codecov]

Codecov Report

❌ Patch coverage is 98.43750% with 1 line in your changes missing coverage. Please review.
✅ Project coverage is 86.36%. Comparing base (40ad457) to head (6230133).

Files with missing lines	Patch %	Lines
...ecks/enforce_member_function_leading_underscore.py	98.41%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##              dev     #135      +/-   ##
==========================================
+ Coverage   85.91%   86.36%   +0.45%     
==========================================
  Files          51       52       +1     
  Lines        1704     1768      +64     
==========================================
+ Hits         1464     1527      +63     
- Misses        240      241       +1     

Flag	Coverage Δ
unittests	86.36% <98.43%> (+0.45%)	⬆️

Flags with carried forward coverage won't be shown. Click here to find out more.

☔ View full report in Codecov by Harness.
📢 Have feedback on the report? Share it here.

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.