Diagrams.net (formerly Draw.io) extension for the Rich Text Editor

Problem to solve

As described and discussed in #20305 (closed), Diagrams.net (formerly Draw.io) offers more advanced features than the standard Mermaid diagrams we support today.

Proposal

Create an extension that embeds, renders, and edits diagrams from Diagrams.net. This list of integrations would be a good place to start looking for how others have implemented it within their apps. Specifically, the Jira/Confluence integration is listed as the most popular extension in the Atlassian marketplace.

Details

Rendering the diagram seems fairly straightforward. Editing, however, could be trickier. Given all the UI necessary to edit the diagram, we may have to open the editor in another window, in full-screen mode, or find some other solution.