Custom callout view?

How can we customize the callout view that is displayed when you click on a pin? I would like to add an image (to the left of the title/subtitle) and some multiline information. A completely custom view would potentially be nice as well.

No files or tests are identified in the issue. Start by locating the map pin callout implementation in ProMotion-map, then determine how an image, multiline information, and a fully custom view could be supported; done means the requested callout customization works when a pin is selected.

Written by the indexing model from the issue text.