[JIRAALIGN-1493] API 2.0 - Update users using PUT doesn't limit the length of the Notes field

Issue Summary

Both the UI and API v1 limit the number of characters length to 4000, but the API v2 doesn't.

With that, if a user updates a record using API 2.0 and adds more the 4K characters in the field Notes, and the try to update the same record using the UI, it is going to throw the following error

"Notes: Text length exceeded - 4000 Characters"

Steps to Reproduce

1. Using the API 2.0 update an user record with +4K characters for Notes
2. Go to "Administration > People"
3. Open the same user record and then click the Save button
4. The error message will show

Expected Results

We should either limit the character length in API 2.0 and show the user an error message.

Actual Results

API saves the data.

Workaround

Don't use more than 4K characters in field Notes.