ECOM-2435

This is a squash of 38 commits ending with
5b080f979d692804452400ac5bed9b17c50b001e

TNL-1914

TNL-1906

Add context for navigation states
added find course to dashboard sidebar and included check for context that Will adds in PR
removed nav_course_search context due to design change so replaced with nav_hidden
Removed rwd_header.js and all references as no longer being used.

Wrapped Find Courses in dashboard sidebar in if statement

adjusting styles for teams cards

- reversing the positions of the sidebar and course listing
- html for new social icons (not currently wired up)
- new actions dropdown for unenrollment and email settings
- partial reorganization of dashboard.scss styles
- text fix for unenrollment
- added missing endif, p/hgroup closures
- reverted la.course-item
- removed extra operator
- fixed broken bok choy test

Co-Authored-By: Jean-Michel Claus <jmc@edx.org>
Co-Authored-By: Brian Talbot <btalbot@edx.org>
Co-Authored-By: Tim Babych <tim@edx.org>
Co-Authored-By: Oleg Marshev <oleg@edx.org>
Co-Authored-By: Chris Rodriguez <crodriguez@edx.org>

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.

Change the reverification failure message styling.

Changing templates so new styles do not appear in courseware.

Removing unused aria tag.

PR comments on cleaning up SASS

Fix signup LMS test.

Copy changes per review on PR

Updating based on PR comments

Style and HTML changes for notifications

LMS-1071

* adds in Sass placeholder to mirror older/inherited button styling used in LMS
* uses light theming Sass variables for button styling
* adds specific selector for certificate download button