Added unit testing

Syrette.Tests/TestTypes.cs

@@ -0,0 +1,35 @@
+namespace Syrette.Tests;
+
+public interface ITestService { }
+public class TestServiceImpl : ITestService { }
+public class TestServiceAlt : ITestService { }
+
+public interface ITestServiceB { }
+public class TestServiceBImpl : ITestServiceB { }
+
+public interface ITestServiceC { }
+public class TestServiceCImpl : ITestServiceC { }
+
+public class TestMultiCtor
+{
+    public ITestService? A { get; }
+    public ITestServiceB? B { get; }
+    public ITestServiceC? C { get; }
+
+    public TestMultiCtor(ITestService a) { A = a; }
+    public TestMultiCtor(ITestService a, ITestServiceB b) { A = a; B = b; }
+    public TestMultiCtor(ITestService a, ITestServiceB b, ITestServiceC c) { A = a; B = b; C = c; }
+}
+
+public class TestDeepService : ITestService
+{
+    public Guid Id { get; }
+
+    public TestDeepService(Guid id) { Id = id; }
+}
+
+public class TestDisposableService : IDisposable
+{
+    public bool IsDisposed { get; private set; }
+    public void Dispose() => IsDisposed = true;
+}