InstantiateNewClassesSniff can be simplified

[aik099]

The https://github.com/joomla/coding-standards/blob/master/Sniffs/Classes/InstantiateNewClassesSniff.php sniff is doing a lot of comparisons inside, but if it really checks that no () are present after new SomeClass then why it's not checking that.

1. find class name, that is created (including namespace)
2. get next non-whitespace char and if it's not ( then return
3. get next non-whitespace char and if it's not ) then report an error and return in other case