Change http.path to http.target in aspnet and aspnetcore instrumentations

[vishweshbankwar]

http.path is not a semantic convention defined by spec. http.path was used in OpenCensus and is mapped to http.target in OpenTelemetry as per this

[codecov]

Codecov Report

Merging #2266 (ffaa169) into main (d649b3d) will increase coverage by 0.02%.
The diff coverage is 100.00%.

@@            Coverage Diff             @@
##             main    #2266      +/-   ##
==========================================
+ Coverage   79.09%   79.12%   +0.02%     
==========================================
  Files         238      238              
  Lines        7488     7488              
==========================================
+ Hits         5923     5925       +2     
+ Misses       1565     1563       -2     

Impacted Files	Coverage Δ
...umentation.AspNet/Implementation/HttpInListener.cs	88.88% <100.00%> (ø)
...tation.AspNetCore/Implementation/HttpInListener.cs	86.23% <100.00%> (ø)
...ter.ZPages/Implementation/ZPagesActivityTracker.cs	97.14% <0.00%> (-2.86%)	⬇️
...emetry.Api/Internal/OpenTelemetryApiEventSource.cs	82.35% <0.00%> (+5.88%)	⬆️
...Zipkin/Implementation/ZipkinExporterEventSource.cs	72.72% <0.00%> (+9.09%)	⬆️

[reyang]

LGTM, consider updating the changelog since this will affect the user.

[utpilla]

We should update SemanticConventions.cs and SpanAttributeConstants.cs in the contrib repo as well to reflect these changes to stay consistent.

https://github.com/open-telemetry/opentelemetry-dotnet-contrib/blob/main/src/OpenTelemetry.Contrib.Shared/Api/SemanticConventions.cs#L52

https://github.com/open-telemetry/opentelemetry-dotnet-contrib/blob/main/src/OpenTelemetry.Contrib.Shared/Api/SpanAttributeConstants.cs#L28

[utpilla]

LGTM. Need to update the contrib repo files with the same changes.