Delete standalone Subsection edit page

[tymofij]

https://openedx.atlassian.net/browse/STUD-1845

• User should not be able to access the Subsection page from anywhere in Studio.
• Mini-outline should no longer link to the Subsection page.
• Breadcrumb should not link to the Subsection page.
• Click on the subsection name on the outline page to edit subsection name.
• Update tests, delete all the code.

Technical details:

• Remove overview.js and overview_spec.coffee
• Remove base.js (or at least as much of it as possible)
• The Lettuce tests should already be gone, but double check
• There were no Bok Choy tests

Implementation question:

All inplace edits were changed to mode "click the text to start editing", as I did not observe this behavior in bulk-publishing branch. Tests pass, but I would like to hear your word on it.

@auraz @polesye please take a look

[polesye]

$('a[rel="external"]').attr({
  'title': gettext('This link will open in a new browser window/tab')),
  'target': '_blank'
});

[polesye]

@tymofij Do we need to remove styles in this PR?

[tymofij]

@cahrens, @frrrances and @andy-armstrong please take a look.

[cahrens]

@frrrances and @explorerleslie, should the subsection be clickable on the unit location sidebar (I imagine it taking you to the outline page, scrolling to the subsection)? Same question for the breadcrumb on the unit page.

[cahrens]

I'm wondering if this should be clickable (going to the outline page).

[cahrens]

Love, love, love all the deleted code. Of course, I can't say if MORE code should have been deleted (well, actually there is one thing I know about-- see the first change in https://github.com/edx/edx-platform/pull/4550).

Had some questions about expected behavior and a few clarifying questions.

Also wondering what CSS can be removed with this PR.

[polesye]

Do we need these styles ?

[cahrens]

BTW, Andy's branch (#4549) has the linking of subsection to outline page (scrolling to the correct location). So you don't need to worry about it in this PR.

[tymofij]

@cahrens Andy's branch (#4549) has the linking of subsection to outline page

Also his branch has correct subsection linked in the breadcrumb in the same manner. Should I drop "unclickable subsection name in breadcrumb" too?

@tymofij Yes (Christina)

[polesye]

Please remove unused after deletion modules: ModuleStoreEnum, Scope, CourseGradingModel.

[tymofij]

Comments were addressed, the PR rebased and ready for final review.

[cahrens]

Can these 2 lines (and related) code be deleted (deleteUnit, createNewUnit). I can't think of anything that would be using them.

[cahrens]

We intended that units.html be deleted. I see it is still referred to in container.html, but I believe that reference can be removed.

units.html used to be used for both the subsection page and for the unit location sidebar on the container page. That sidebar has been rewritten and has its own templates now.

[cahrens]

TriggerChangeEventOnEnter is now unused and can be removed.

[tymofij]

@cahrens TriggerChangeEventOnEnter is now unused and can be removed.

removed, as well as things related to units.html

[cahrens]

👍 Looks good to merge (test failures all seem unrelated)