Consider json5 as template format

[evorios]

Prerequisites

• I have written a descriptive issue title
• I have searched existing issues to ensure a similar issue has not already been created

Description

To use the scripting engine on mock templates, most of times there is a need to write an invalid JSON structure, like this:

{
  "request": {
    "method": "PUT",
    "route": "customers/{id}"
    "condition": "<#=
      var isAuthCorrect = Request.Header["Authorization"]?.ToString() == "Basic bG9naW46cGFzc3dvcmQ=";
      return isAuthCorrect;
    #>"
  },
  "response": {
    "status": "OK",
    "body": {
      "url": "<#= Request.Url?.ToString() #>",
      "customerId": "<#= Request.Route["id"]?.ToString() #>",
      "acceptHeader": "<#= Request.Header["Content-Type"]?.ToString() #>",
      "queryString": "<#= Request.Query["dummy"]?.ToString() #>",
      "requestBodyAttribute": "<#= Request.Body["address"]?[0]?.ToString() #>"
    },
    "indented": false
  }
}

Proposed solution

json5 seems to be suitable alternative to write templates with C# scripts, as it is more permissive on content, like the example bellow, which is a completely valid json5:

{
  request: {
    method: 'PUT',
    route: 'customers/{id}',
    condition: '<#=\
      var isAuthCorrect = Request.Header["Authorization"]?.ToString() == "Basic bG9naW46cGFzc3dvcmQ=";\
      return isAuthCorrect;\
    #>'
  },
  response: {
    status: 'OK',
    body: {
      url: '<#= Request.Url?.ToString() #>',
      customerId: '<#= Request.Route["id"]?.ToString() #>',
      acceptHeader: '<#= Request.Header["Content-Type"]?.ToString() #>',
      queryString: '<#= Request.Query["dummy"]?.ToString() #>',
      requestBodyAttribute: '<#= Request.Body["address"]?[0]?.ToString() #>'
    },
    indented: false
  }
}

Alternatives

nop

Additional context

There are some disadvantages using json5:

• no fully supported by vscode;
• need to append c#-strings by symbol '\' for multiline code.