Course Outline: Container Card Placeholder - Drag (Add Sidebar Flow A)

[ChrisChV]

Figma: https://www.figma.com/design/4wsTUbieYphB2qchIPxm10/%E2%9C%8F%EF%B8%8F-Library---Course-Authoring-v1.0--Open-edX-?node-id=18894-131824&t=CRhnGsvcV9oVySlp-4

In Scope:

• When the use clicks any button implemented in Course Outline: Add "Container" buttons #2628, one card is created in the selected place
• The user can drag the card in the context of the item to select another location
• The cancel button, deletes the card and closes the Add Sidebar implemented in Course Outline: Add Sidebar (In-location flow) #2631