Add custom renderer for images

What does this MR do?

This MR adds a custom renderer for images in the Static Site Editor and also adds the ability to pass metadata to custom renderers.

Note: This is an iteration towards delivering #218531 (closed)

Screenshots (strongly suggested)

No visual changes are expected

Does this MR meet the acceptance criteria?

Conformity

• Changelog entry (not needed)
• Documentation (if required) (not needed)
• Code review guidelines
• Merge request performance guidelines
• Style guides

Availability and Testing

• Review and add/update tests for this feature/bug. Consider all test levels. See the Test Planning Process.
• Tested in all supported browsers
• Informed Infrastructure department of a default or new setting change, if applicable per definition of done

Related to #218531 (closed)