Merge release back to master

[REVMI-41] Test changes made to course blocks API

handle missing fields on access denied blocks

Merge release back to master

Doing this as a merge because the release is backlogged and we need
to make smaller increments onto the RC which have some changes that
don't land on master till much later.

The change we're missing on master is an upgrade of the newrelic plugin
that fixes a major memory issues for us.

WL-1908: Version bump to get edx-enterprise 1.3.10

Clarify partially enabled state in the FBE support tool

INCR-190

revert pillow version

* INCR-185 Modernize common/lib/xmodule/xmodule/assetstore and contentstore

* Adding check for python version when making integer contracts

ENT-1334: Fix: SSO users last_login set to NULL

Upgrade newrelic agent to fix a memory leak in Python 2

- The very first time a user signed in through SSO their ```last_login```
  field on the ```auth_user``` table was set to NULL instead of the
  appropriate time stamp.  This fixes that issue.

INCR-128

Remove dependence on microsite factory.

ARCH-607 Add API view for retrieving third party auth user status.

Merge pull request #20119 from edx/testeng/bokchoy_auto_cache_update_f2440cac82cfce5547d42c8bf9504468bee4a743

Bokchoy db cache update

INCR-187

INCR-186

* INCR-108: Run python-modernize on openedx/core/lib

* Fixed urlencode import

* Fixed diff quality warnings and six.string_types error

* Fixed pickle import

* Fixed iteritems import

* Fixed ungrouped imports

* Fixed six.moves import issues

Remove flaky test test_birth_year_not_set

INCR-156 Migrated and cleaned up imports on /common/lib/capa/capa/tests/

Remove course listing from user tab of sysadmin

BB-755 Add feature to manually unlock a student account after too many login attempts.

Remove unused 'plot' references in sysadmin