Add a Country content type with its listing, cards and full page layout

Problem/Motivation

Countries are the backbone of the site template: every programme, story and figure is reported per country. Today a single Country Page canvas page stands in for all of them, so a site builder cannot add a country, and the country layout cannot be reused, listed, filtered or referenced.

The design defines a full country page: a hero with the country name, summary and image, "Our Role", "On the Ground", a key-figures panel, key partners, related updates and a listing of the other countries.

Steps to reproduce

1. Install the Horizon Aid site template.
2. Go to /country-page: a single hand-built canvas page.
3. Go to /admin/content and try to add a country: there is no Country content type.

Proposed resolution

Add a Country content type the way Varbase Blog Base manages a content type, and remove the stand-in canvas page.

• Content type country with the fields the design needs: summary, featured image, our role, on the ground (text and image), figures description, three key figures (number and description), and key partners.
• Form display, card and overlay_card_medium view displays, and the matching Drupal Canvas content templates.
• A countries view with block displays for the listing and the "see other countries" section.
• A pathauto pattern so a country lives at /countries/[node:title].
• The full Canvas template implements the design: hero, Our Role, On the Ground, By the Numbers, Key Country Partners.
• Five demo countries with their own high resolution images: Afghanistan, Ecuador, Kenya, Lebanon and Ukraine.
• Remove the Country Page canvas page and any menu link that pointed at it.

Remaining tasks

• ✅ File an issue about this project
• ❌ Addition/Change/Update/Fix to this project
• ❌ Testing to ensure no regression
• ➖ Automated unit/functional testing coverage
• ➖ Developer Documentation support on feature change/addition
• ➖ User Guide Documentation support on feature change/addition
• ➖ UX/UI designer responsibilities
• ➖ Accessibility and Readability
• ❌ Reviewed by a human
• ❌ Code review by maintainers
• ❌ Full testing and approval
• ❌ Credit contributors
• ❌ Review with the product owner
• ❌ Update Release Notes
• ❌ Release

User interface changes

• A Country content type is available, and countries are published at /countries/[node:title].
• The Country Page canvas page no longer ships.

API changes

• N/A

Data model changes

• New content type country, and new node fields: field_our_role, field_on_the_ground, field_on_the_ground_image, field_figures_description, field_figure_number, field_figure_description, field_partners.

Release notes snippet

• Added a Country content type with its listing, card and full page layouts, and replaced the single Country Page canvas page with real country content.