[WebProfilerBundle][Form] Add information about form synchronization err...

| Q             | A
| ------------- | ---
| Bug fix?      | no
| New feature?  | yes
| BC breaks?    | no
| Deprecations? | no
| Tests pass?   | yes
| Fixed tickets | #9891, #9989, #5607
| License       | MIT
| Doc PR        | 

When form data transformation fails, the origin error message is lost. This error shouldn't be shown to user, because this is technical error, so maybe a good idea is to show transformation failures in web profiler in `form` panel below `errors` section?

There are no BC-breaks in this PR, I have added public internal method to `Symfony\Component\Form\Form` class, that returns `TransformationFailedException`, it is used by `FormDataExtractor`. `Symfony\Component\Form\FormInterface` has not been touched by me, because that would be a BC-break.
Small detail: we are using `null !== xxx` in Symfony.