Add an Upcoming events block display to the events view

Problem/Motivation

This recipe already reshapes views.view.events, which is owned by the third-party drupal/events recipe, and contributes a related block display through a config action. What it does not contribute is a small "upcoming events" display, the obvious companion piece for a homepage or sidebar panel.

Without one, a site template has to define that display itself. The Educare site template did exactly that, carrying roughly three hundred lines of events-view configuration in its own recipe.yml — a definition no other consumer of this recipe can reuse, in a file that should not own it.

Proposed resolution

Add a latest block display to the existing views.view.events config action, alongside the related display this recipe already contributes:

• three upcoming events, no pager;
• the text_card_medium view mode, already bound to field_when so each card carries its date;
• a single column, so it fits a narrow column beside other content.

Component ids are the base theme's (vartheme_bs5:), matching the displays this recipe already declares, so a site on vartheme_bs5 works as shipped and a site template with its own theme repoints them through setViewsComponentStyleTheme.

Remaining tasks

• ✅ File an issue
• ❌ Addition/Change/Update/Fix
• ❌ Testing to ensure no regression
• ➖ Automated unit testing coverage
• ➖ Automated functional testing coverage
• ➖ UX/UI designer responsibilities
• ➖ Readability
• ➖ Accessibility
• ➖ Performance
• ➖ Security
• ➖ Developer Documentation
• ➖ User Guide Documentation
• ➖ Reviewed by human
• ➖ Code review by maintainers
• ➖ Full testing and approval
• ➖ Credit contributors
• ➖ Review with the product owner
• ✅ Release notes snippet
• ✅ Release varbase_events_base-1.0.0-alpha2

User interface changes

• A new "Upcoming events" block becomes available to place.

API changes

• N/A

Data model changes

• New latest block display on views.view.events, contributed by this recipe's config action.

Release notes snippet

• Added an Upcoming events block display, listing the next three events as dated cards.