Add Spectre.Cli to Spectre.Console

* Renames Spectre.Cli to Spectre.Console.Cli.
* Now uses Verify with Spectre.Console.Cli tests.
* Removes some duplicate definitions.

Closes #168

examples/Cli/Injection/Infrastructure/TypeRegistrar.cs

@@ -0,0 +1,31 @@
+using System;
+using Microsoft.Extensions.DependencyInjection;
+using Spectre.Console.Cli;
+
+namespace Injection
+{
+    public sealed class TypeRegistrar : ITypeRegistrar
+    {
+        private readonly IServiceCollection _builder;
+
+        public TypeRegistrar(IServiceCollection builder)
+        {
+            _builder = builder;
+        }
+
+        public ITypeResolver Build()
+        {
+            return new TypeResolver(_builder.BuildServiceProvider());
+        }
+
+        public void Register(Type service, Type implementation)
+        {
+            _builder.AddSingleton(service, implementation);
+        }
+
+        public void RegisterInstance(Type service, object implementation)
+        {
+            _builder.AddSingleton(service, implementation);
+        }
+    }
+}

examples/Cli/Injection/Infrastructure/TypeResolver.cs

@@ -0,0 +1,21 @@
+using System;
+using Microsoft.Extensions.DependencyInjection;
+using Spectre.Console.Cli;
+
+namespace Injection
+{
+    public sealed class TypeResolver : ITypeResolver
+    {
+        private readonly IServiceProvider _provider;
+
+        public TypeResolver(IServiceProvider provider)
+        {
+            _provider = provider ?? throw new ArgumentNullException(nameof(provider));
+        }
+
+        public object Resolve(Type type)
+        {
+            return _provider.GetRequiredService(type);
+        }
+    }
+}