Define a provision to interact with `dotnet new` based CLI templates within Visual Studio via the IWizard interface implementation

[egvijayanand]

Is your feature request related to a problem? Please describe.

There exists a provision to interact with Visual Studio wizards via custom assemblies with types implementing the IWizard interfaces.

For this to happen, the concrete type implementing the IWizard interface needs to be defined in the .vstemplate file (for classic template types).

Only the relevant section is shown for brevity.

<VSTemplate>
  <WizardExtension>
    <!-- Assembly should be signed -->
    <!-- Fully qualified name of the assembly with PublicKeyToken -->
    <Assembly></Assembly>
    <!-- Full qualified name of the type implementing the IWizard / IWizard2 interface -->
    <FullClassName></FullClassName>
  </WizardExtension>
</VSTemplate>

Describe the solution you'd like.

A similar provision is required in the template.json or even in the ide.host.json file to fill in the assembly and type details and the corresponding invocation to happen during the appropriate events. Making it easier to work with dotnet new templates within VS.

Additional context

https://github.com/sayedihashimi/template-sample#how-to-ship-a-template-inside-of-a-visual-studio-extension-vsix