Add DashboardRunCommand as subcommand of DashboardCommand

Refactor the dashboard command so that 'aspire dashboard' is now a parent
command that shows help, and 'aspire dashboard run' contains all the
original dashboard-starting logic.

- Create DashboardRunCommand with all existing dashboard execution logic
- Convert DashboardCommand to a parent command that shows help
- Add RunDescription resource string and update xlf files
- Register DashboardRunCommand in DI (Program.cs and test helper)
- Rename tests to DashboardRunCommandTests

Author: JamesNK

src/Aspire.Cli/Commands/DashboardCommand.cs

@@ -456,6 +456,7 @@ internal static async Task<IHost> BuildApplicationAsync(string[] args, CliStartu
         builder.Services.AddTransient<CertificatesTrustCommand>();
         builder.Services.AddTransient<DoctorCommand>();
         builder.Services.AddTransient<DashboardCommand>();
+        builder.Services.AddTransient<DashboardRunCommand>();
         builder.Services.AddTransient<UpdateCommand>();
         builder.Services.AddTransient<DeployCommand>();
         builder.Services.AddTransient<DoCommand>();

src/Aspire.Cli/Commands/DashboardRunCommand.cs

@@ -118,6 +118,9 @@
     <value>System.Resources.ResXResourceWriter, System.Windows.Forms, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089</value>
   </resheader>
   <data name="Description" xml:space="preserve">
+    <value>Manage the Aspire dashboard</value>
+  </data>
+  <data name="RunDescription" xml:space="preserve">
     <value>Start the Aspire dashboard</value>
   </data>
   <data name="BundleNotAvailable" xml:space="preserve">