Fix 'int' widget's maximum value

It looks the changes made by NXP-21815 (user of IntegerConverter instead of NumberConverter) has brought down the allowed maximum value to 2,147,483,647, which is the maximum integer value for a 32-bit integer.
How to reproduce:

• create a new document type
• in its schema, add an Integer field with the following validation rules:
  • check Numeric range
  • set Maximum to 999999999999 and check its included box
• use a Integer widget for the Integer field in the Creation layout of the document type
• deploy

When creating a document of the document type above and providing the value 3123456789 to the Integer field, the validation error '3123456789' is not a number. Example: 9346 is shown, it should not.