Added support of per-extension assembly isolation (#1431)

* Added support of per-extension assembly isolation

* Added some comments

Author: veler

src/app/dev/DevToys.Core/Mef/AssemblyIsolation.cs

@@ -0,0 +1,26 @@
+using System.Reflection;
+using System.Runtime.Loader;
+
+namespace DevToys.Core.Mef;
+
+// See https://learn.microsoft.com/en-us/dotnet/core/dependency-loading/understanding-assemblyloadcontext
+internal sealed class AssemblyIsolation : AssemblyLoadContext
+{
+    private readonly AssemblyDependencyResolver _resolver;
+
+    internal AssemblyIsolation(string entryPointAssemblyPath)
+    {
+        _resolver = new AssemblyDependencyResolver(entryPointAssemblyPath);
+    }
+
+    protected override Assembly? Load(AssemblyName assemblyName)
+    {
+        string? assemblyPath = _resolver.ResolveAssemblyToPath(assemblyName);
+        if (assemblyPath != null)
+        {
+            return LoadFromAssemblyPath(assemblyPath);
+        }
+
+        return null;
+    }
+}

src/app/dev/DevToys.Core/Mef/RecursiveDirectoryCatalog.cs

@@ -14,6 +14,7 @@ internal sealed partial class RecursiveDirectoryCatalog : ComposablePartCatalog,
 {
     private readonly ILogger _logger;
     private readonly string _path;
+    private AssemblyIsolation? _assemblyIsolation;
     private AggregateCatalog? _aggregateCatalog;
 
     /// <summary>
@@ -122,7 +123,13 @@ private bool AddLibraryToMefCatalog(string filePath)
         try
         {
             AssemblyCount++;
-            var asmCat = new AssemblyCatalog(filePath);
+
+            // Create an isolation context for the plugin.
+            // This allows to load dependencies version that the plugin asks, even if DevToys uses a different version of that same dependency.
+            _assemblyIsolation ??= new AssemblyIsolation(filePath);
+
+            Assembly assembly = _assemblyIsolation.LoadFromAssemblyPath(filePath);
+            var asmCat = new AssemblyCatalog(assembly);
 
             // Force MEF to load the plugin and figure out if there are any exports
             // good assemblies will not throw the RTLE exception and can be added to the catalog