[Instrumentation.AspNetCore, Instrumentation.Http] Fix http.request.method_original attribute

[Kielek]

Fixes open-telemetry/opentelemetry-dotnet-contrib#1607 (comment)
Design discussion issue #

Changes

Propagates changes from open-telemetry/opentelemetry-dotnet-contrib#1607 related to http.request.method_original

Merge requirement checklist

• CONTRIBUTING guidelines followed (license requirements, nullable enabled, static analysis, etc.)
• Unit tests added/updated
• Appropriate CHANGELOG.md files updated for non-trivial changes
• [ ] Changes in public API reviewed (if applicable)

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 85.53%. Comparing base (6250307) to head (bb346b1).
Report is 147 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #5471      +/-   ##
==========================================
+ Coverage   83.38%   85.53%   +2.15%     
==========================================
  Files         297      290       -7     
  Lines       12531    12606      +75     
==========================================
+ Hits        10449    10783     +334     
+ Misses       2082     1823     -259     

Flag	Coverage Δ
unittests	?
unittests-Instrumentation-Experimental	24.19% <ø> (?)
unittests-Instrumentation-Stable	24.22% <ø> (?)
unittests-Solution-Experimental	85.48% <ø> (?)
unittests-Solution-Stable	85.52% <ø> (?)

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

see 64 files with indirect coverage changes

[Kielek]

@vishweshbankwar, first part of propagation fixes from open-telemetry/opentelemetry-dotnet-contrib#1607. Please review, and merge if possible.