Support anonymous users with new (Blockstore-based) XBlock Runtime

Instantiate idv attempt with a string photo_id_key.

Implementation details:
* Anonymous users are assigned a unique ID (like 
  `anon42c08f9996194e2a9339`) which gets stored in the django session.
  `block.scope_ids.user_id` and `block.runtime.anonymous_student_id`
  will both return this value.
* User state for anonymous users is stored in the django cache and
  automatically expires as the cache gets pruned. Because user state is
  stored, anonymous users can use interactive blocks like capa problems.
* There is no mechanism for upgrading to a registered account and
  keeping user state since the user state store for anonymous users
  (EphemeralKeyValueStore) is completely different than the one for
  registered users (DjangoKeyValueStore/"CSM"), and has no "list all
  keys" functionality.
* "User State Summary" field values are shared among [recently active]
  anonymous users but are not shared with registered users.
* Anonymous users can only access the `public_view` of XBlocks, not the
  regular `student_view`.

When we run the management command, the photo_id_key is retrieved
through the orm and so is represented as a string.  However, when we do
the initial attempt, the object is instantiated and we refer to the key
without having decoded it.  The photo_id_key is sent as a part of the
request to software secure.  And if we have a byte representation their
signature checking will fail.

This is why the management command worked even when the site didn't.
It was getting a cleaned key via the orm.

Fix the bug where we return many programs if the number of courses the staff user is enrolled in are many

OverwriteStorage was removed from django-storages, so pull it into ed…

Correct the output file name for exports.

Support transcript files for video XBlocks in Blockstore

Rename order in CreditRequirement (1/3)

Upgrade edx-ora2 to fix studio edit view.

Added management command to add coursemode history from snapshot.

There was a serialization issue with one of the studio JS assets that
is rendered as a part of the edit view.

ENT-2452, ENT-2068 | Made the lms and learner portal alerts responsiv…

Ensure that certificate is not generated if a learner enrolled in
audit mode is whitelisted

PROD-978

This stage does the following:

- Adds the new field and migration to create the column.
- Makes all* writes go to both old and new field.

(*) Except for writes from the Django Admin for this model.  I confirmed
with Support that CreditRequirements are never edited through the Django
Admin interface.  Additionally, I confirmed via the django_admin_log
that there is no record of anybody changing any CreditRequirements.

Updated the django-countries to support Django 2.2

Ensure that photo verification data is correctly typed.

DISCO-1522: check if enrolled before congrats message

* add api function and teams service

This helps out the Verified Only case where the user
is not first enrolled as an audit learner.

[REV-1064] show discount in sidebar and sock

Make the file name not have a 'b' prefix.

There were cases where we needed to encode things to codecs other than
ascii.  In these cases, python returns byte strings but we needed them
to be unicode so that they serialize correctly later when we combine
them with other unicode strings.

DISCO-1414 org source of truth

INCR-562 @require_certificate_permission parameters added

We make sure the temp file name is a string because we combine it with
other string components with path later.

Make sure the content is a string for json response.

-point to updated edx-organizations package

ENT-2505 | By passing the check for forcing the login by third auth when user is…

Upgrade to coverage 5.0