This patch adds support for creating Group Input nodes by dragging input sockets
and panels from the group interface tree-view in the side bar. This
significantly simplifies creating a Group Input node for a specific input when
there are lots of them.
These cases are supported:
* Dragging an input socket creates a Group Input node just for that socket.
* Dragging a panel without panel-toggle creates a Group Input node containing
all sockets in the panel.
* Dragging a panel with panel-toggle creates a Group Input for the panel-toggle.
* Dragging a panel with panel-toggle while holding Ctrl creates a Group Input
with the panel-toggle and all sockets in the panel.
This is supported in all node tree types.
Pull Request: https://projects.blender.org/blender/blender/pulls/137739
309ce182b8