Validation for fields of type "Long" just ignores illegal characters without showing any message (with patch)

Validation for fields of type "Long" just ignores illegal characters without showing any message.

Steps to reproduce this on the CMS:

1. On an existing document type add a new field of type Long.
2. Create a new document of the type you just modified.
3. On the new field of type Long, add some illegal characters (I would consider something like "123Example123" illegal)
4. Save the document
   • Expected result: There is some feedback showing you have an invalid input; Actual result: It seems like the document is saved, you still see your "illegal" input, however checking the console you can see that all the fields are saved, except your illegal input.
5. Save and close the document
   • Expected result: There is some feedback showing you have an invalid input; Actual result: The document closes and it seems like it is saved correctly, however your input is no longer there. Checking the console you have the same results as before.