Secured Signing; added option to extend the Due Date of an Electronic Signature

A new function has been added to Secured Signing to extend the Due Date of an Electronic Signature.

The Summary Page defines a constant for the number of days to extend by - from today.

An additional "Extend" or "Shorten" button is shown along with other actions at the top of the page.

The following built-in Summary Page has been updated:

"SummaryPage2_ElectronicSignatureSummary_SecuredSigning" has been updated to version: 2.06 on 24/12/2019.