Form get directly dirty state if API returns new data

[alexander-schranz]

Q	A
Sulu Version	2.5.14 / 2.4.19 / 2.6.0-RC1
Sulu Form Bundle	2.5.2
PHP Version	-

Actual Behavior

Form get directly dirty if API returns new data.

Expected Behavior

The form should not get dirty

Steps to Reproduce

1. Create a dynamic form via the SuluFormBundle
2. Add a new field
3. Click Save
4. Save button get again dirty

The form bundle requires to generate a key and id and returns that think that hook into to trigger again dirty state.

This confuses the content manager as they think navigating away sulu shows "unsaved data" message.