Add PHP Analyzer Plugin and Composer Lock Data Handling

- Implemented the PhpAnalyzerPlugin to analyze PHP projects.
- Created ComposerLockData class to represent data from composer.lock files.
- Developed ComposerLockReader to load and parse composer.lock files asynchronously.
- Introduced ComposerPackage class to encapsulate package details.
- Added PhpPackage class to represent PHP packages with metadata and evidence.
- Implemented PhpPackageCollector to gather packages from ComposerLockData.
- Created PhpLanguageAnalyzer to perform analysis and emit results.
- Added capability signals for known PHP frameworks and CMS.
- Developed unit tests for the PHP language analyzer and its components.
- Included sample composer.lock and expected output for testing.
- Updated project files for the new PHP analyzer library and tests.

src/Graph/StellaOps.Graph.Indexer/Incremental/GraphChangeStreamServiceCollectionExtensions.cs

@@ -0,0 +1,28 @@
+using System;
+using Microsoft.Extensions.DependencyInjection;
+using Microsoft.Extensions.Options;
+
+namespace StellaOps.Graph.Indexer.Incremental;
+
+public static class GraphChangeStreamServiceCollectionExtensions
+{
+    public static IServiceCollection AddGraphChangeStreamProcessor(
+        this IServiceCollection services,
+        Action<GraphChangeStreamOptions>? configureOptions = null)
+    {
+        ArgumentNullException.ThrowIfNull(services);
+
+        if (configureOptions is not null)
+        {
+            services.Configure(configureOptions);
+        }
+        else
+        {
+            services.Configure<GraphChangeStreamOptions>(_ => { });
+        }
+
+        services.AddSingleton<GraphBackfillMetrics>();
+        services.AddHostedService<GraphChangeStreamProcessor>();
+        return services;
+    }
+}