Specialized ArgumentReadNode for the different Arguments classes (Unary, Binary, ...)

Signed-off-by: Stefan Marr <git@stefan-marr.de>
Moved creation of CatchNonLocalReturnNode to MethodGenerationContext

Think it doesn't belong into the Parser.

Signed-off-by: Stefan Marr <git@stefan-marr.de>
Removed `executeObject()`

This is covered by `executeGeneric`, I think.

Signed-off-by: Stefan Marr <git@stefan-marr.de>