HY-1666 Add options to scrollbars

[Jira Ticket](https://jira.webfilings.com/browse/HY-1666)

## 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.