Issue #3437118 by Grimreaper, pdureau: Add card image overlay

Closes #3437118

templates/patterns/card_overlay/card_overlay.ui_patterns.yml

+card_overlay:
+  label: "Card overlay"
+  description: "Turn an image into a card background and overlay your card’s text. Depending on the image, you may or may not need additional styles or utilities."
+  links:
+    - 'https://getbootstrap.com/docs/5.3/components/card/#image-overlays'
+  category: "Card"
+  settings:
+    heading_level:
+      type: "select"
+      label: "Heading level"
+      options:
+        2: "h2"
+        3: "h3"
+        4: "h4"
+        5: "h5 (Default)"
+        6: "h6"
+      preview: 5
+      allow_expose: true
+      allow_token: true
+  fields:
+    image:
+      type: "render"
+      label: "Image"
+      description: "Card image."
+      preview:
+        theme: "image"
+        uri: "data:image/svg+xml;base64,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"
+        alt: "© 2017 John Smith photography"
+    title:
+      type: "text"
+      label: "Title"
+      description: "Card title. Plain text."
+      preview: "Card title"
+    subtitle:
+      type: "text"
+      label: "Subtitle"
+      description: "Card subtitle. Plain text."
+      preview: "Card subtitle"
+    text:
+      type: "text"
+      label: "Text"
+      description: "Card text. Plain text."
+      preview: "This is a wider card with supporting text below as a natural lead-in to additional content. This content is a little bit longer."
+    content:
+      type: "render"
+      label: "Content"
+      description: "Free content outside of any wrapper."
+      preview:
+        type: "html_tag"
+        tag: "p"
+        value: "<small>Last updated 3 mins ago</small>"
+        attributes:
+          class:
+            - "card-text"
+    links:
+      type: "render"
+      label: "Links"
+      description: "Array of link elements"
+      preview:
+        - type: "html_tag"
+          tag: "a"
+          value: "Card link"
+          attributes:
+            href: "#"
+        - type: "html_tag"
+          tag: "a"
+          value: "Another link"
+          attributes:
+            href: "#"