LEARNER-1854

This includes several general enhancement in addition
to the fixes for unified_course_view:
1. Add support for default when no waffle flag defined.
2. Add support for table_blacklist to assertNumQueries.
3. Rename flag to 'course_experience.course_outline_page'.
4. Change flag default to True when it is not defined.

Adding a reviews page to the course and updating the reviews module on the course about page. Removed the existing coursetalk implementation and put it in a fragment, removed the tests as well. Added configuration settings to specify the reviews template as well as the reviews provider. This is all protected by a waffle flag.

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.

LEARNER-877

LEARNER-879

LEARNER-609

LEARNER-607

LEARNER-606

Move lms.lib.xblock into lms.djangoapps.lms_xblock in preparation add database backed configuration to it