Add native Parceler support

Now Parcelar is supported without any extra dependencies or converters.

To use it, change @arg to @arg(parceler = true) before any element that you want to wrap and unwrap by Parceler.

Migration steps:

1. There is no more dependency on the extra module. Parceler has now native support. You need to have a dependency to Parceler!
2. Delete converter in configuration
3. Change @arg to @arg(parceler = true) before any element that you want to wrap and unwrap by Parceler.