KRACOEUS-7539: add validate user attached form

I'd rather see this work with a UserAttachedFormContract rather than a Document Object if you don't want it on the pd doc.  In fact, something that was done which should probably be corrected is the FormGeneratorService should be changed to the following signature:

```
FormValidationResult validateForms(ProposalDevelopmentContract pdDoc) throws S2SException;
FormGenerationResult generateAndValidateForms(ProposalDevelopmentContract pdDoc) throws S2SException;

//this is your new method
FormValidationResult validateUserAttachedForms(Collection<? extends UserAttachedFormContract> userAttachedForms) throws S2SException;
```