Clean up of WebProfiler Controller classes

 - Added missing "@throws" PHPdoc comments in controllers:
 - Updated deprecated reference to Symfony\Component\HttpKernel\Debug\ExceptionHandler to use Symfony\Component\Debug\ExceptionHandler instead

| Q             | A
| ------------- | ---
| Bug fix?      | no
| New feature?  | no
| BC breaks?    | no
| Deprecations? | no