urldecode(), urlencode() respects encoding
urldecode(), urlencode() respects encoding

- fixes https://github.com/peachpiecompiler/peachpie/issues/527
- see Context.StringEncoding

peachpiecompiler/peachpie,iolevel/peachpie-concept,iolevel/peachpie-concept,iolevel/peachpie-concept,peachpiecompiler/peachpie,iolevel/peachpie,iolevel/peachpie,iolevel/peachpie,peachpiecompiler/peachpie