chore: Address profiler warnings

[chynesNR]

This addresses a number of compiler and linter warnings in the Profiler:

• Moved some large XML objects from stack to heap. Since XML parsing isn't done during instrumentation it feels like a safe change.
• Made a number of member functions const
• Addressed a number of uninitialized variables (They were all set before use; this is just to make the compiler happy)
• Disabled warnings for a couple of the CoreCLR headers that we include but are not owned by the profiler.
• Changed a lot of loop iterators from auto to auto&, to avoid an unnecessary copy. This could in theory result in a behavior change but I don't think any of them were deliberate.

There are still a few linter warnings that I don't want to change (e.g. in the CoreClr headers), but Visual Studio doesn't have a way to exclude files from lint.

All unit and integration tests are passing with the new Profiler.

[codecov-commenter]

Codecov Report

Attention: Patch coverage is 96.29630% with 1 line in your changes missing coverage. Please review.

Project coverage is 80.58%. Comparing base (332529b) to head (7c5b151).
Report is 6 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #2545      +/-   ##
==========================================
+ Coverage   80.49%   80.58%   +0.09%     
==========================================
  Files         459      459              
  Lines       28873    28927      +54     
  Branches     3167     3177      +10     
==========================================
+ Hits        23240    23311      +71     
+ Misses       4846     4825      -21     
- Partials      787      791       +4     

Flag	Coverage Δ
Agent	81.47% <ø> (+<0.01%)	⬆️
Profiler	72.59% <96.29%> (+0.87%)	⬆️

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

Files	Coverage Δ
...nt/NewRelic/Profiler/Configuration/Configuration.h	82.69% <100.00%> (+7.69%)	⬆️
...lic/Profiler/Configuration/IgnoreInstrumentation.h	100.00% <ø> (ø)
...filer/Configuration/InstrumentationConfiguration.h	93.11% <100.00%> (-0.13%)	⬇️
...elic/Profiler/Configuration/InstrumentationPoint.h	100.00% <ø> (ø)
...filer/MethodRewriter/ExceptionHandlerManipulator.h	73.91% <100.00%> (-0.38%)	⬇️
...elic/Profiler/MethodRewriter/FunctionManipulator.h	51.40% <ø> (ø)
.../NewRelic/Profiler/MethodRewriter/InstructionSet.h	55.48% <100.00%> (ø)
...ler/MethodRewriter/InstrumentFunctionManipulator.h	94.78% <100.00%> (+0.09%)	⬆️
.../NewRelic/Profiler/MethodRewriter/MethodRewriter.h	94.73% <100.00%> (-0.14%)	⬇️
...rc/Agent/NewRelic/Profiler/SignatureParser/Types.h	62.04% <75.00%> (+0.05%)	⬆️

... and 6 files with indirect coverage changes