Trackig issue: drag-and-drop improvement

[abey79]

Dragging entities from/to the blueprint tree/streams tree/viewport

TL;DR: this is high value (but needs work)

Summary table

↓ to / from →	Blueprint tree	Streams tree	Viewport
Blueprint tree: Existing container	🫳	🫳	❌
Blueprint tree: Existing view	🫳	🫳	❌
Viewport: Existing view	#8266 (need design)	#8266 (need design)	🫳 (too complex for value)
Viewport: New view (aka in between existing views)	#8267 (need design, complex)	#8267 (need design, complex)	🫳 (too complex for value)

❌: meaningless
🫳: postpone

Related issues

• Support dragging entities to existing view to add them to their filter #8266
• Support dragging entities to the viewport to create new views #8267

Dragging containers/views from/to the blueprint tree and viewport

TL;DR: we're basically good as is.

Summary table:

↓ to / from →	Blueprint tree	Viewport
Blueprint tree: Existing container	✅	🫳
Blueprint tree: Existing view	❌	❌
Viewport: Existing container	🫳	✅

✅: done
❌: meaningless
🫳: postpone

Other high priority items

• Support drag-and-drop for sensible multi-selections #8275
• When dragging, display a pill with a summary of what's being dragged next to the cursor #8276

[teh-cmc]

I would add this one to the list 😶 :

• Clicking a SpaceView bar immediately triggers drag-n-drop #6124