Section attributes and attachments

[jrtcppv]

To facilitate description of groups of media, make sections first class entities. They also need to support file attachments although at first pass attachment cloning does not need to be supported. Subtasks to complete are:

• Create a new SectionType endpoint
• Add new fields to Section: foreign key to SectionType, JSONField attributes, and JSONField attachments
• Expose attribute search and edit in the Section endpoint
• Add section attributes to section creation dialog
• Add attribute display panel for selected sections in project detail view
• Add interface for viewing/downloading section attachments