HY-1666 Add options to scrollbars

## Problem

Right now scrollbars can only be configured through CSS, some of the options should be able to be configured through code.

## Solution

Allow options to be configured through code.

## Tests

Added.

## QA / +10

Check out branch. Tests should pass, no regressions.
This is why significant others get frustrated with programmers.  :stuck_out_tongue_winking_eye: