LEARNER-1628
This allows enrolled users to write reviews on the reviews page that
can be accessed through the course tools sidebar. A button in the top
corner of the page toggles the widget that is configured with a
setting in the common.py file. The reviews tool is Course Talk.
This lets us consolidate chunks of JavaScript that are common to
multiple bundles, so that they can live in their own shared file. This
will be more relevant when we have UI components -- there's actually
very little shared code right now.
This sock sits at the bottom of both the home and the course content pages. It allows the user to click a 'Learn More' button to open a panel that allows the user to navigate to the upgrade checkout page. The sock is only shown for users that have not yet upgraded in a course that has a verification upgrade date that has not yet passed. Python tests cover the various course mode and upgrade dates.
