Expand and enhance clipboard functionality & UI

[chris-steele]

Feature description

Goals:

1. be able to copy/cut any component/block/article/page from anywhere in a course and paste to any other point in the same course or a different course.
2. make it easier and more intuitive to perform cut/copy/paste actions
3. provide a clipboard that can hold mulitple items

Can you work on this feature?

• I can contribute

[chris-steele]

Update: goals 1 and 2 completed. Goal 3 proposed for a later release.

[chris-steele]

#253
adapt-security/adapt-authoring-content#18