Minor code corrections after review
J2K: minor fix
More correct line breaks counting in converter
Better diagnostic for Element has no prototype error
Converter should not fail completely if some error occured in the after conversion pass
J2K converter: refactored code moving code for converting class body into separate class
KT-5492 J2K: convert field with getter/setter to property

 #KT-5492 Fixed
Refactored StatementVisitor to StatementConverter (similar to ExpressionConverter before) + renamed ExpressionVisitor