fix: Refactor to eliminate usage of .GetAwaiter().GetResult() in Framework builds. (#2534)

[tippmar-nr]

Refactors HttpCollectorWire.Send() to remove usage of .GetAwaiter().GetResult(), which required additional refactoring in IHttpClient and IHttpContentWrapper.

With this change, there are now no usages of .GetAwaiter().GetResult() in code built for the .NET Framework target.

Resolves #2534

[codecov-commenter]

Codecov Report

Attention: Patch coverage is 80.00000% with 2 lines in your changes missing coverage. Please review.

Project coverage is 80.50%. Comparing base (227003a) to head (26e7d24).

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #2535      +/-   ##
==========================================
+ Coverage   80.47%   80.50%   +0.02%     
==========================================
  Files         459      459              
  Lines       28775    28873      +98     
  Branches     3153     3167      +14     
==========================================
+ Hits        23158    23244      +86     
- Misses       4837     4843       +6     
- Partials      780      786       +6     

Flag	Coverage Δ
Agent	81.49% <80.00%> (+0.02%)	⬆️
Profiler	71.71% <ø> (ø)

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

Files	Coverage Δ
.../Agent/Core/DataTransport/Client/HttpClientBase.cs	84.09% <ø> (ø)
...ic/Agent/Core/DataTransport/Client/HttpResponse.cs	79.41% <100.00%> (-10.59%)	⬇️
...ic/Agent/Core/DataTransport/Client/NRHttpClient.cs	78.43% <100.00%> (-14.91%)	⬇️
...nt/Core/DataTransport/Client/NRWebRequestClient.cs	89.79% <100.00%> (-10.21%)	⬇️
...elic/Agent/Core/DataTransport/HttpCollectorWire.cs	88.13% <100.00%> (ø)
...nt/Core/DataTransport/Client/HttpContentWrapper.cs	0.00% <0.00%> (ø)
...e/DataTransport/Client/WebRequestClientResponse.cs	91.17% <50.00%> (ø)

... and 2 files with indirect coverage changes