Infoset valid member (a boolean indicating if the item is valid or not) should be set by Validation

An alternative to turning on validation and having to deal with warning messages is to build the valid/not-valid information into the infoset.

Turns out the DFDL Spec allows for this. Infoset Items have a 'valid' member which is a boolean indicating whether the item is valid or not. (See DFDL Spec section 4.1.2).

When validation is enabled, we should populate this member.

Hopefully there are standard ways to represent the information of a PSVI, that are settable/accessible from JDOM/DOM.

(If not we can invent one like: dafext:valid="true", or similar).