UnusedUse - fix false negative when namespace shortname equals imported namespace shortname

UnusedUse - fix false negative when namespace shortname equals imported namespace shortname
need to have all namespace declarations to deal with
```php
namespace Foo\A;
use Bar\A;
```

As I said, I do not add support for it here. So there are no good or wrong architecture for supporting it - couse there are no 'it' inside.

In worst case of scenario you talking about the fixer will not remove unused use statement that can be removed - just like on master