Add in metric tracking to xqueue.

Covers external grading and certificates.
Converted XModule to JavaScript. Added Jasmine tests.

Part of the process for removing CoffeeScript from
edx-platform dependencies. Covering XModule with JavaScript
Jasmine unit tests.
Merge pull request #3144 from edx/diana/monitor-xqueue-graders

Add in metric tracking to xqueue.
Remove unused function
Centralize when json parsing of responses from controller_query_service happens
Merge pull request #3126 from edx/valera/convert_xmodule_to_javascript

Converting XModule module to JS.
Fixed nested bullets to enable PDF

4 levels of bullets don’t work with latex

DOC-250
Updating ora2 requirements
Fix a decode error in course_about.html and make some string translatable

The strings in share links should be in unicode, otherwise when the name of a course is non-ascii, it will generate a decode error.
And some of these strings is actually translatable, so they should be collected into mako.po.
Improve inline discussion UI

1. Add space between threads
2. Change Show/Hide to Expand/Collapse and visually separate it
3. Limit a thread to 700px high and scroll if longer

Co-authored-by: marco <marcotuts@gmail.com>
Fixes LMS-2474 by ensuring that readElts reads always reads an element
Merge pull request #3159 from edx/sanchez/ora2-deploy

Updating ora2 requirements
Emit datadog events for all course enrollments, not just those outside of verified courses
Merge pull request #3110 from edx/gprice/inline-visual-fixup

Improve inline discussion UI
Merge pull request #3134 from edx/dcs/a11y-gentle-alert

Fixes LMS-2474 by ensuring that readElts reads always reads an element
Merge pull request #3157 from edx/markhoeber/documentation/PDF-fix

Fixed nested bullets to enable PDF
Collect metrics around the open_ended_grading controller_query_service
Correctly catch RubricParsingErrors
Make GradingServices always return dictionaries, rather than sometimes returning strings
Record metrics about the peer grading service