Add @Normalized contraint that validates if text is normalized in a given form

I propose the addition of `@Normalized` that validates that a character sequence is normalized to a given form.

It can be important to check normalization as part of validation to ensure that further validation works as expected.

References:

• https://docs.oracle.com/javase/7/docs/api/java/text/Normalizer.html#isNormalized(java.lang.CharSequence,%20java.text.Normalizer.Form)

• https://www.informit.com/articles/article.aspx?p=1751371&seqNum=4

• https://wiki.sei.cmu.edu/confluence/display/java/IDS01-J.+Normalize+strings+before+validating+them