Adds staff and instructor users of the master course to CCX

[amir-qayyum-khan]

Background

fixes #126, fixes #155, fixes #115 and fixes #205

This is an updated version of https://github.com/edx/edx-platform/pull/10877 which had to be reverted.

What is done in this PR

Studio Updates:

• Remove ccx from staff dashboard inside studio. Because a master course can have unlimited ccx, staff's dashboard can be populated with a huge list of ccx along with master course

LMS Updates:

• This is for course staff to see what ccx coaches are doing with course.
• Now when a coach creates a new ccx, I am assigning staff role on this ccx course to all staff of master course.
• Added instructors of master course as instructor(s) in ccx.
• Also adds the master course staff users to new CCX created via the CCX REST APIs
• Note: This code will add/enrol staff and instructors in ccx and now max student limit for ccx depends on number of staff and admins.
• Fixed view as student issue on ccx, now staff can view as student and see how ccx view will appear to student
• Fixed display name on ccx coach dashboard. Previously it was show display name of master course on coach dashboard.

To run migration manually on devstack

• python manage.py lms migrate ccx 0003 --settings=devstack

  To reverse migration manually on devstack

• python manage.py lms migrate ccx 0002 --settings=devstack

@pdpinch @giocalitri

• Staff on Master course
  
• Staff on CCX
  
• Admin/instructors on master course
  
• Admin/instructors on ccx
  

Fixed view as student

Fixed display name of ccx on coach dashboard.

[pdpinch]

This looks to have all the changes I asked for, but the diff isn't correct because master doesn't include the revert from bf5d203

Can you update the cover letter to explain that this updates & restores 91bf48f which was reverted by bf5d203. Also, we need to cut the title down. It's way too long.

[pdpinch]

@giocalitri has some concerns about the reverse migration which he brought up over chat.

I am now confident that the 0002 reverse migration cannot work as it is 
because during the migration all the `lazy` decorated methods of the 
CCX model cannot be found.

this is how the reverse migration should be to work:

def reverse_add_master_course_staff_to_ccx_for_existing_ccx(apps, schema_editor):
    """
    Add all staff and admin of master course to respective CCX(s).
    """
    CustomCourseForEdX = apps.get_model("ccx", "CustomCourseForEdX")
    list_ccx = CustomCourseForEdX.objects.all()
    store = modulestore()
    for ccx in list_ccx:
        with store.bulk_operations(ccx.course_id):
            course = store.get_course(ccx.course_id)
        ccx_locator = CCXLocator.from_course_locator(ccx.course_id, unicode(ccx.id))
        reverse_add_master_course_staff_to_ccx(course, ccx_locator, ccx.display_name)

[giocalitri]

@pdpinch since we are talking about this, he may wants to make the migration self contained and not import the functions from utils

he also needs to import modulestore

[giocalitri]

@pdpinch I also would like to take a deep look at this PR once you give your thumbsup.

[giocalitri]

This PR should include the entire code currently in #207, given that most of that PR is about tests missing in the previous code and the actual changes in the rest APIs are trivial.

[giocalitri]

@pdpinch what do you think? ^^

[pdpinch]

Yeah. I don't think you'll pass coverage without the changes to test_utils.

[amir-qayyum-khan]

@pdpinch @giocalitri done with adding tests for studio. (Test to check that ccx course filter out in studio dashboard).

[giocalitri]

I believe the convention is to use a single _

[amir-qayyum-khan]

• @giocalitri i think we use single _ for gettext and for unused variables we sue __,

• pylintrc take __ and _ as good name,

  please see

[giocalitri]

yeah, i just remembered

[giocalitri]

this is good to go on edx 👍

[giocalitri]

please squash before opening the PR against edx

[amir-qayyum-khan]

made PR upstream https://github.com/edx/edx-platform/pull/11787