* Add test for IsACallSniff.
* Fix doublicate finds in IsACallSniff and
InstantiationWithObjectManagerSniff.
* Both didn't stop looking for class at end of expression.
Relates: #46
* As we migrated trait to class, all sniffs have to extend instead to
use the new class.
* Also make PhpCsFile import and type hints the same across all sniffs.
Relates: #36
* As we sometimes have to fix classnames inside a string, move this
common work to trait.
* Also make classname "free" of string quotes inside the check, not the
concrete sniffs.
