Use default interfaces for getting and setting headers (#31519)

src/Antiforgery/src/Internal/DefaultAntiforgery.cs

src/Antiforgery/test/DefaultAntiforgeryTest.cs

src/Antiforgery/test/DefaultAntiforgeryTokenStoreTest.cs

...DB2C.UI/test/AzureAdB2COpenIDConnectEventHandlersTests.cs

...e/samples/AzureAppServicesHostingStartupSample/Startup.cs

src/Azure/samples/AzureAppServicesSample/Startup.cs

...nents/WebAssembly/Server/src/ContentEncodingNegotiator.cs

...est/testassets/TestServer/Controllers/PersonController.cs

src/Hosting/Hosting/src/Internal/ErrorPageBuilder.cs

...ing/Hosting/src/Internal/HostingApplicationDiagnostics.cs

src/Hosting/TestHost/test/ClientHandlerTests.cs

src/Hosting/TestHost/test/HttpContextBuilderTests.cs

src/Hosting/TestHost/test/TestServerTests.cs

src/Http/Headers/src/HeaderNames.cs

src/Http/Headers/src/PublicAPI.Unshipped.txt

src/Http/Http.Extensions/src/RequestHeaders.cs

src/Http/Http.Extensions/src/ResponseExtensions.cs

src/Http/Http.Extensions/src/ResponseHeaders.cs

...ttp.Extensions/test/HeaderDictionaryTypeExtensionsTest.cs

src/Http/Http.Extensions/test/ResponseExtensionTests.cs