Investigate the best way to include custom icons into our system

[kerri-augenstein]

Look at various ways to enable using icons.

Requirements

• Easy to change the color of the icon using css
• Use custom icons created by designers in Figma

[yvonnetangsu]

We're going with the mask method so we can change the svg icon colors using background-color in css. However, IE doesn't understand mask, so we'll be hiding the icons in IE since they are not absolutely necessary.