ECOM-3940

SASS compilation variable conventions update, focusing on basic colors, baseline variable usage for padding and margins, ui-depth extends, along with other small fixes. The intent with this is to not have any user-facing impact, and instead move us closer toward having files that use our newer sass conventions.

Bourbon's box-shadow mixin has been deprecated, and they recommend to use the
official spec.

The official border-radius mixins were deprecated and removed in Bourbon 3.0.
https://github.com/thoughtbot/bourbon/pull/95

pearson registration - revised contact calls to action and order in status section, edited flash message copy/styling, added in strawman state for disabled form/closed registration state of form, added in strawman state for demographics rejected flash message, revised accomodations text labe and isntructions

renames some scss files for better orginization, sets fixed widths on main containers to avoid akward scaling issues untill media queries can be added for more responsive scaling