Implement theme admin UI to support previewing

LEARNER-2017

Educator-9 Removed comment about changing warning to exception

Upgrade edx-enterprise package to 0.39.1.

PLAT-1590 Fixes for Docker Devstack e2e tests

EDUCATOR-842: adds in management command for verified_tracks

bump edx-sga XBlock to v0.6.4

Re-add to BlockStructure cache on miss.

This model will soon be deleted.

LEARNER-2042

EDUCATOR-842: adds in management command to swap a course's xblocks from verified track cohorts to enrollment tracks

BlockStructures are stored in S3, but they're cached in memcached. Prior
to this commit, they were only written to memcached when first created.
This commit adds a write to repopulate the cache entry every time there
is a cache miss. Hopefully, this will help reduce the miss rate we're
seeing.

Make HTTP 500 error pages site-aware

Catch exception with duplicate username/email

Fixing whitelabel messaging issue.

WL-1147

Switching edx.org and openedx images.

Handle tab hiding at a different level.

Template were using global TECH_SUPPORT_EMAIL for error pages. This
changes them to use the site email if there is one.

Return no libraries if org not specified

Upgrade django-oauth-toolkit to 0.12.0

[ENT-491] Check for Enterprise-linked TPA pipeline when asked for Enterprise on request

Due to a bug in org=None vs org='', all libraries were being returned
from the "optimization" in #15292. This fix returns no libraries on the
default '' value.

LEARNER-2016 Cannot Track Campaigns to Checkout Page Using UTM Codes

include webpack commons bundle on all pages

Fixed user dropdown alignment

Background color changed for microsoft button in social auth login

include webpack commons bundle on all pages

quotes

homegrown webpack_loader mock

toggle installed webpack_loader in test env file instead

fix test checking context

Move the user_attribute creation for site 

Added a missing parameter.

LEARNER-741

EDUCATOR-760

LEARNER-2016