Improve violation path on assert message when validating arrays

[andrepimpao]

As an example, when validating an array with collection and a name was given, the assert message would not display the index in the array where the error occurred.

$input = ['name' => ''];

Validator::collection([
  'name' => Validator::notBlank()->getConstraints()
])->assert($input, name: 'collection');

Would throw the following exception message collection: This value should not be blank..
With the fix, returns collection[name]: This value should not be blank..