Merge upstream; bump d3-dag

• fix: bump d3-dag version f4af7e5
• Merge 3.2.1 from upstream d4ea44d
• 3.2.1 22624a3
• chore(ts): updates typings for CustomNodeElementProps a28e72c
• Add handlers to custom node element (bkrem#372) d538b08
• 3.2.0 7e92f20
• docs: tweaks prop documentation for hasInteractiveNodes 38b2c4a
• refactor(demo): simplifes MixedNodeInputElement example be623ac
• fix(demo): fixes order of custom node element options 75c4b73
• Add 'hasInteractiveNodes' prop to Tree that enables/disables d3 drag and pan handlers on foreignObject nodes (bkrem#370) cfec09a
• doc: set up demo 51e55da

v0.1.1...v0.1.2