PROD-I-753 Add a left/right scroll bar in mapping page (Word docs)

When mapping a Word doc, there is no scroll bar that allows you to scroll left or right on the document. (There is a up/down scroll bar only.) This is not helpful especially when the document scrolls to the right while mapping... The only way you can scroll back to the left is if you click and drag your mouse to the left as if you were highlighting an area to the left of the doc. This is not intuitive at all and I've received comments about this during training. Please see attached screenshot for an example