Replace StructureMap IoC container with Microsoft IoC

CHANGELOG.md

@@ -39,6 +39,7 @@ and this project adheres to [Semantic Versioning](http://semver.org/).
 
 ### Changed
 
+- [SIL.LCModel] Replaced the internal StructureMap (`structuremap.patched`) IoC container with `Microsoft.Extensions.DependencyInjection` (8.x). No public API change.
 - [SIL.LCModel] Trim 12 overwordy semantic domain descriptions and fix 22 punctuation/whitespace issues in the SemDom.xml template, matching sillsdev/FwLocalizations#5 and sillsdev/FwLocalizations#7
 - [SIL.LCModel] `FileUtils.IsFileUriOrPath` checks for the presence of "file:" rather than the absence of known non-file URI schemes
 - Changed to target .Net Framework 4.6.2 instead of 4.6.1

src/SIL.LCModel/Application/Impl/DomainDataByFlid.cs

@@ -42,7 +42,7 @@ internal sealed class DomainDataByFlid : ISilDataAccessManaged
 		/// Therefore, one should not use them for multi-session identity.
 		/// CmObject identity can only be guaranteed by using their Guids (or using '==' in code).
 		/// </remarks>
-		internal DomainDataByFlid(ICmObjectRepository cmObjectRepository, IStTextRepository stTxtRepository,
+		public DomainDataByFlid(ICmObjectRepository cmObjectRepository, IStTextRepository stTxtRepository,
 			IFwMetaDataCacheManaged mdc, ISilDataAccessHelperInternal uowService,
 			ILgWritingSystemFactory wsf)
 		{

src/SIL.LCModel/ILcmServiceLocator.cs

@@ -117,9 +117,9 @@ public static TService GetInstance<TService>(this IServiceProvider provider)
 
 		public static IEnumerable<TService> GetAllInstances<TService>(this IServiceProvider provider)
 		{
-			//structure map might not work the same way as the standard service provider, so we need to handle it separately.
+			// A CommonServiceLocator-based provider exposes GetAllInstances directly.
 			if (provider is IServiceLocator serviceLocator) return serviceLocator.GetAllInstances<TService>();
-			//the standard service provider handles listing all services like this, however that might not work the same in structure map if an IEnumerable is explicitly registered.
+			// A plain IServiceProvider resolves all registrations as an IEnumerable<T>.
 			return (IEnumerable<TService>) provider.GetService(typeof(IEnumerable<TService>));
 		}
 	}