Fix KeyError issue with empty course structures

ENT-318: Update activation email subject and message text

EDUCATOR-340

When enabled, these changes prevent LMS application code from hitting the discovery service in-process to retrieve programs. Instead, program data is pulled from cache entries populated by a management command, cache_programs.

LEARNER-382

LEARNER-868: Default unified_course_view on in devstack.

Neem/handle iter errors

Only try to render dates when user is authenticated.

ECOM-6602 Change buy certificate button style

ECOM-6602

Fix broken Python certificate tests

ENT-361: Allow hiding of IDP selection page during SSO

Enable course sidebar for new course home page

This prevents the LMS from requesting details for programs which the command hasn't been able to cache yet, which would throw off monitoring we'll be setting up to keep an eye on missing entries.

LEARNER-382

LEARNER-764

Re-create image set for course overview.

EDU-218

TNL-6870 Add masquerading feature for preview mode

Add course dates fragment to new sidebar

Also add it to the course home page.

LEARNER-821 -Visual adjustments to course outline

Mako should be able to render even if webpack hasn't run

Make tests and coverage work with openedx/features

Add management command for caching program data

This command requests every available program from the discovery service, writing each to its own cache entry with an indefinite expiration. It is meant to be run on a scheduled basis and should be the only code updating these cache entries.

LEARNER-382

EDUCATOR-218 – Add logging

mattdrayer/ENT-328: Update account activation message on sign-in form.

ENT-351/ENT-362 Enterprise package version bump