Individual action buttons for datasets and resources

[paulmueller]

Action buttons:

• [x] view on DCOR (0.6.0)
• ~copy ID~ (no real use case)
• [x] open in Shape-Out (via drag&drop in 0.6.0)
• [ ] generate Shape-Out session (only for collections and datasets)
• ~share with user~ (in sharing tab)
• ~add to collection~ (via tool button)
• [x] download resource(s) (for all)
• [ ] download condensed resource(s) (for all)
• [ ] follow collection/circle/dataset (make sure following a collection will make it show up in "my data")