Swift Concurrency support

[samueleperricone]

Async Await function are not currently supported and breaks the conversion.

Example:

protocol MyProtocol {
    func myFunction() async -> MyData
}

Should translates to:

interface MyProtocol {
    suspend fun myFunction(): MyData
}

Similarly when invoking the function, the await keyword can be removed:

let myData = await myFunction()

Should translates to:

val myData = myFunction()