Implement drag and drop for children in the layers panel

[johno]

No description provided.

[Caryyon]

@johno is this blocks once they have been placed or is this inner content within a block within the layers panel?

[johno]

For the inner content inside the block within layers panel on the left. Ideally all nodes in the layers panel tree could be drag and droppable wherever. But to start we can do sibling nodes.

[colebemis]

atlaskit/tree looks promising for this.

[Caryyon]

@colebemis this library seems to be lost. I'll take a look at some other approaches.