Add support for TypeScript in the integration tests

[MangelMaxime]

When working on #4007 , I wanted to add an integration test to cover comments generation but because right the Integration runs for JavaScript we can't test the TypeScript output.

Code I wanted to test:

module ParamObject

open Fable.Core

/// This is a user, a very strange individual which will find each and every edge case existing.
[<AllowNullLiteral>]
[<Global>]
type User [<ParamObjectAttribute; Emit("$0")>] (id: int, ?name: string, ?age: int) =
    /// Id used for id stuff
    member val id = id with get, set
    /// name used for naming conventions
    member val name: string option = jsNative with get, set
    /// age because you never tell age
    member val age: int option = jsNative with get, set