Improve error messaging when template tabs are placed off-page during envelope creation

When using document template, the sender sees this error when creating an envelope: "We're unable to create a new envelope. Check your connection and try again."

However, the real cause (visible only in a HAR file, not in account API logs) is:
"TAB_OUT_OF_BOUNDS" - "Tab is placed off of the page. Tab is located off of page [number]"

Based solely on the error message displayed on Docusign web page, the user has no way to know that a field was off-page. A clearer message would have let them fix it themselves without having to contact Docusign Support.

For this reason, the customer requests that, when envelope creation fails due to out-of-bounds tabs in a template, show a clear, actionable message, for example:

"We couldn’t create this envelope because one or more fields are placed off the page in template <template name>, page <page number>. Please move the field(s) within the page boundaries and try again."

This will reflect the real cause of the issue and indicate template and page so the user can correct it.