Decorators improvements

[Marek Bartoš]

• split into 3 interfaces (RequestDecorator, ResponseDecorator, ErrorDecorator), drop decorator type tag in DI (only priority could be defined if needed)
• if an error decorator return null then next in a row should be tried
• request decorator accept only request
• request and response decorators should be able to throw EarlyReturnResponseException (and error decorator maybe too?)