[Epic] [TypeSpec Authoring] scenario: authoring the API payload for API specification in typespec

[chunyu3]

Problem:
When user write API specification in typespec, it is hard for user to figure out the API specification payload especially when the typespec code using Azure template. As a result, user may not be able to verify if the typespec API specification match his needs.

This feature aims to provide an authoring capability that can automatically generate API payload directly from TypeSpec code.

Expected Behavior
prompt: show the api payload for following typespec code:

model Widget{
  name: string;
  location: string;
  tags?: Record<string>;
}

interface Wedget {
    createOrUpdateWidget is Operations.LongRunningResourceCreateOrUpdate<Widget>;
}

Expected output

patch /widgets/{widgetName}

{
"name": "Widget",
"location": "eastus",
"tags": {
"env": "test"
}
}