Update analyzer redirecting VS extension

[jjonescz]

Follow up on #42861.

• Added opt out env var.
• Set SystemComponent=true so the extension doesn't show up in the list of installed VS extensions.
• Added logging.
• Moved the deployed analyzers under CommonExtensions and removed version numbers from the layout (this was in preparation for enabling NGEN which was determined to not be needed after all, but I still think the new layout is better).

[Copilot]

Pull Request Overview

This PR updates the analyzer redirecting VS extension to complete the implementation following up on a previous PR. Key changes include adding an opt-out environment variable, improving the VS extension configuration, and restructuring the analyzer layout.

• Added logging capabilities and opt-out environment variable (DOTNET_ANALYZER_REDIRECTING)
• Restructured analyzer deployment layout to remove version numbers from directories
• Updated VS extension to be a system component that doesn't appear in installed extensions list

Reviewed Changes

Copilot reviewed 9 out of 9 changed files in this pull request and generated 4 comments.

Show a summary per file

File	Description
test/Microsoft.Net.Sdk.AnalyzerRedirecting.Tests/SdkAnalyzerAssemblyRedirectorTests.cs	Updated tests to use new metadata-based version tracking instead of version directories
src/Tasks/sdk-tasks/sdk-tasks.InTree.targets	Added new MSBuild task ProcessRuntimeAnalyzerVersions for version extraction
src/Tasks/sdk-tasks/ProcessRuntimeAnalyzerVersions.cs	New task to extract version numbers and create metadata JSON file
src/Tasks/sdk-tasks/GenerateRuntimeAnalyzersSWR.cs	Updated layout paths and added metadata.json file inclusion
src/Microsoft.Net.Sdk.AnalyzerRedirecting/source.extension.vsixmanifest	Updated to VS 19.0 compatibility and system component configuration
src/Microsoft.Net.Sdk.AnalyzerRedirecting/SdkAnalyzerAssemblyRedirector.cs	Added logging, opt-out mechanism, and updated to use metadata-based version lookup
src/Microsoft.Net.Sdk.AnalyzerRedirecting/Microsoft.Net.Sdk.AnalyzerRedirecting.csproj	Added System.Text.Json dependency for metadata processing
src/Layout/VS.Redist.Common.Net.Core.SDK.RuntimeAnalyzers/VS.Redist.Common.Net.Core.SDK.RuntimeAnalyzers.proj	Updated build process to use new version extraction and VS extension configuration
documentation/general/analyzer-redirecting.md	Updated documentation to reflect new metadata-based approach

[jjonescz]

@JoeRobich @RikkiGibson @333fred for reviews, thanks

Btw, I think I can merge this into release/10.0.1xx as it's infra-only change because the package doesn't ship inside SDK, it is only for VS insertion - and that also needs a special PR to "activate" this new extension, until then it won't be inserted automatically alongside .NET.