Need custom events listing block

[skleinfeldt]

Event listing items should show title, summary, teaser image (or lead image if no teaser), and event start date. Display upcoming items only in chronological order by event date (soonest first).

Mockup to come.

[davisagli]

This is related to https://github.com/plone/volto/issues/4765 which is planned for volto core