[discussion] Add Diagram and Flow components?

*⚠️ Info: This issue is for product research, to gather community input. In this [base-ui repo](https://github.com/mui/base-ui) we are, currently, focused on the core set of components needed to create a great design system, so the probability we build this in this repo is very low.*

## Summary

## Examples in other libraries

- https://github.com/xyflow/xyflow
- https://x6.antv.antgroup.com/
- https://www.syncfusion.com/react-components/react-diagram
- https://github.com/mermaid-js

*([internal benchmark](https://www.notion.so/mui-org/x-Diagram-Flow-component-1c1cbfe7b66080ee8ed8e887e19820f8))*

## Motivation

TBD

- User requests:
- /
- UI library requests:
- https://github.com/shadcn-ui/ui/issues/10468