PackChk should not report .cc as invalid C++ extension (#1121)

[spcaipers-arm]

• PackChk should not report .cc as invalid C++ extension: SDCMSIS-1306
• Added test
• Added Destroy() to ErrLog class

[github-actions]

Test Results

  7 files   53 suites   5m 36s ⏱️
185 tests 168 ✅ 17 💤 0 ❌
692 runs  624 ✅ 68 💤 0 ❌

Results for commit c45f4e0.

♻️ This comment has been updated with latest results.

[codecov]

Codecov Report

Attention: Patch coverage is 69.23077% with 12 lines in your changes missing coverage. Please review.

Project coverage is 65.42%. Comparing base (2d97e20) to head (c45f4e0).
Report is 1 commits behind head on main.

Files with missing lines	Patch %	Lines
.../packchk/test/integtests/src/PackChkIntegTests.cpp	71.05%	2 Missing and 9 partials ⚠️
tools/packchk/src/CheckFiles.cpp	0.00%	0 Missing and 1 partial ⚠️

Additional details and impacted files

@@           Coverage Diff           @@
##             main    #1950   +/-   ##
=======================================
  Coverage   65.42%   65.42%           
=======================================
  Files         173      173           
  Lines       35039    35054   +15     
  Branches    20352    20357    +5     
=======================================
+ Hits        22923    22934   +11     
+ Misses       7908     7906    -2     
- Partials     4208     4214    +6     

Flag	Coverage Δ
buildmgr-cov	73.94% <ø> (ø)
packchk-cov	67.95% <69.23%> (+0.08%)	⬆️

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

Files with missing lines	Coverage Δ
tools/packchk/src/CheckFiles.cpp	67.73% <0.00%> (+0.49%)	⬆️
.../packchk/test/integtests/src/PackChkIntegTests.cpp	68.80% <71.05%> (+0.15%)	⬆️

... and 3 files with indirect coverage changes