Updates to account and profile APIs based on arch council feedback

SOL-258 Removing preview and content type from search list for sequence ...

Combine the changes of SOL-199 and SOL-221

Multi-commit history:
- hide drag functionality for entrance exam section.
- hide entrance exam subsection elements e.g. delete, drag, name etc.
- show unit/verticals expanded in case of entrance exam
- modify code in order to allow user to update entrance exam score from UI.
- write down unit tests.
- write down Jasmine tests.
- add bok-choy test
- updated bok-choy test
- internationalize string
- repositioned sequential block creatori
- SOL-221 (entrance exam message)
- SOL-199 LMS Part (show entrance exam content) and hide the course navigation bar.
- redirect the view in case of entrance exam.
- update code structure as per suggestions
- write down unit tests
- fix pep8
- instead of hiding the exam requirement message, now also showing the exam the completion message (success state).
- write down unit test to show exam completion message.
- Update code as per review suggestions
- update doc string
- addressed review suggestions
- change sequential message text
- css adjustments
- added new css class for entrance exam score in studio
- added Jasmine test for remaning coverage
- sequential message should appear under the context of entrance exam subsection.
- updated text in CMS and LMS as per suggestions.
- added unit text to insure sequential message should not be present in other chapters rather then entrance exam.
- skip setter if empty prerequisite course list
- exclude logic from xblock_info.js that is specifically related to entrance exam.
- added js tests and updated code as per suggestions
- added tests
- addressed several PR issues
- Several small fixes (style, refactoring)
- Fixed score update issue
- added some more unit tests.
- code suggested changes.
- addressed PR feedback

return proper 404 for assets of some invalid course from split modulesto...

PLAT-456

Upgrade PDF.js library from v0.8.1243 -> v1.0.907

Switch to api directory.

china video cdn experiment

ECOM-1140: Instructor dashboard example certificates

Match Studio logo logic to LMS

Add flaky decorator.

Allow global staff to generate example certificates
on the instructor dashboard.

Allow global staff to enable/disable self-generated
certificates for a course.

Change .md file to .rst.

Related to TNL-1642.

Related to TNL-1619.

Fix failing forums unit test.

Ned/finish pr 7232

Certificate status when XQueue is unavailable.

Add empty introspection rule for BlockTypeKeyField.

Use 'edx_lint write' to create our pylintrc from pylintrc_tweaks

Revert "Merge pull request #6771 from edx/dan-f/forums-filter-discussion...

Awais786/ecom 1158 upgrade page

Show a select box when editing a library content block (SOL-123)

use 'commit_on_success' transaction decorator to avoid registering users...