Use native Canvas features for image export

[nikku]

Proposed Changes

This follows https://github.com/camunda/web-modeler/pull/18432 to use native (on board) facilities to render a diagram SVG to an image.

Checklist

To ensure you provided everything we need to look at your PR:

• Brief textual description of the changes present
• Visual demo attached
• Steps to try out present, i.e. using the @bpmn-io/sr tool
• Related issue linked via Closes {LINK_TO_ISSUE} or Related to {LINK_TO_ISSUE}

[github-actions]

This Pull Request targets develop branch, but contains fix commits.

Consider targeting main instead.