[Demo]: add scrolling to invalid fields on form demo

# Description
Shifting the focus on the page when the mandatory fields are filled in incorrectly.

## Now:
If the mandatory fields are filled incorrectly and the "Validate" or "Save" button is clicked, User doesn't see the highlighted incorrectly filled fields, since the focus remains at the bottom of the page.

## To Do:
If the mandatory fields are filled incorrectly and User clicks on the "Validate" or "Save" button, User sees highlighted incorrectly filled fields, as the focus on the page moves up to these fields.