feat(joint-react): support for HTML rendering outside the graph

[samuelgja]

Description

Add support for render HTML elements outside the graph via new property inside the paper:

  /**
   * Enabled if renderElements is render to pure HTML elements.
   * By default, `joint/react` renderElements to SVG elements, so for using HTML elements without this prop, you need to use `foreignObject` element.
   * @default false
   */
  readonly isHTMLRendererEnabled?: boolean;

If enabled, renderElement is HTML instead of SVG.

Motivation and Context

This provides us support for safari browser and other browsers which do not support foreignObject properly.

Screenshots (if appropriate):

Screen.Recording.2025-05-01.at.13.56.50.mov