Fix VSN Form's Validation rules & Make each project sees and manages only its own forms

Fix form creation and update, including validation rules persistence.

Changes:

• Validation rules update: Populate validation rules when updating existing fields during form update (previously left empty in FieldRequestResponseMapper.updateEntity).

• applicable_field_type: Set this field from the field type when creating ValidationRules so the NOT NULL constraint on validation_rules is respected.

• field_id: Set the Field on ValidationRules (vr.setField(entity)) so the field_id foreign key is persisted and the NOT NULL constraint is satisfied.

• Extend ValidationRulesRequestResponseMapper with toEntity(dto, FieldType) and use it in FieldRequestResponseMapper when creating validation rules.

Isolate forms per project for multi-project deployments

Each project (e.g. VSN, CheckAndGo) can use the same forms service while only seeing and managing its own forms. Existing projects like CheckAndGo keep access to all forms. New projects such as VSN only access their own forms.