Provide debug pretty printers as part of Qt

Having handwritten dumpers in multiple backends like in Qt Creator and the Visual Studio extension is not quite otimal for a consistent and up to date debugging experience of Qt based applications. Additionally every new tool that wants to debug Qt based applications has to write new dumpers.

Providing the dumpers in the native debugger format like natvis for the msvc debugger or type summary for lldb would ease the pain on the backends and simplify adding useful debugging to new Tools like VS Code or for old folks that like to directly use the debugger from the commandline.