Comment Node Feature Request

[dlandry]

Describe the feature you'd like
I'd like to request a feature that allows users to add visible comments to each node in the graph. These comments should be toggleable between fully visible, summary view, or hidden. The aim is to clarify the node's purpose and configuration.

Additional context
The implementation could be any of:

• additional comment field in each node
• comment node that can be attached to any other 'standard' node
• separate comment node that can be 'grouped' to any specific node or set of nodes (ie. drop a comment node onto the canvas, and select/multi-select the comment node and the relevant 'standard nodes' to which the comment node refers. Mark the grouped nodes with an outline and background color, and/or allow the grouped nodes to be represented by one image with the comment summary title being the visible title of the grouped nodes.)

[HenryHengZJ]

Added sticky note - #1513 that allow user to mark down/comment on the canvas. Future improvements can be made like turning on/off, grouping etc