Adding the Highlight Signature Indicator
Adding the HighlightSignature indicator to a tranaction is slightly different depending
onthe schema associatd with the document.

- For the TXN Schema, the HighlightSignatureIndicator is at
the root level of TXN. Add the HighlightSignatureIndicator attribute and
then set the indicator to True/Yes/1.

- For the VMPMISMO Schema, the HighlightSignatureIndicator
is at the Loan/_CLOSING_DOCUMENTS level.

