Refactoring create_course_utils and create_library_utils to reduce the amount of differences (mostly renames

Users are unlikely to change their organization name.

The only supported mode is currently 'random', so it doesn't make sense
to expose the 'mode' in the edit form.

It looks like the 'New Course'/'New Library' buttons on the studio home page.

Clicking the 'Add Component' button scrolls down to the 'Add New Component' buttons.

'aria-required="true"' is implied when 'required' is present.

Most of the updates are related to the My Courses -> Studio Home change.

This changes the style of the inactive libraries/courses tab when hovering.

Only the active tab on the dashboard page gets the blue underline.
When hovering over an inactive tab, the color of the text changes,
but the underline does not appear.

Retriggering Jenkins

* Added tests for `problem_types` CapaDescriptor property
* Improved indentation in tests
* Improved validation messages

than libraries and filtering allow