perf: load images lazily on the country information page

Inspired by #1508

Author: php-coder

Diff for: src/main/webapp/WEB-INF/views/country/info.html

@@ -97,6 +97,7 @@ <h3 id="page-header" th:text="${#strings.capitalize(header)}">
 									th:with="label=|${countryName}, ${desc}|"
 									alt="Italy, Prehistoric animals, 1999, 7&nbsp;stamps (imperf.)"
 									title="Italy, Prehistoric animals, 1999, 7&nbsp;stamps (imperf.)"
+									loading="lazy"
 									th:alt="${label}"
 									th:title="${label}"
 									th:src="@{${GET_IMAGE_PREVIEW_PAGE}(id=${series.previewId})}" />
@@ -112,37 +113,55 @@ <h3 id="page-header" th:text="${#strings.capitalize(header)}">
 						</figure>
 						<figure>
 							<a href="../series/info.html">
-								<img src="http://via.placeholder.com/250" alt="Italy, Prehistoric animals, 22&nbsp;stamps" title="Italy, Prehistoric animals, 22&nbsp;stamps" />
+								<img src="http://via.placeholder.com/250"
+									alt="Italy, Prehistoric animals, 22&nbsp;stamps"
+									title="Italy, Prehistoric animals, 22&nbsp;stamps"
+									loading="lazy" />
 							</a>
 							<figcaption><a href="../series/info.html">Prehistoric animals, 22&nbsp;stamps</a></figcaption>
 						</figure>
 						<figure>
 							<a href="../series/info.html">
-								<img src="http://via.placeholder.com/250" alt="Italy, Cartoons, 2005, 5&nbsp;stamps" title="Italy, Cartoons, 2005, 5&nbsp;stamps" />
+								<img src="http://via.placeholder.com/250"
+									alt="Italy, Cartoons, 2005, 5&nbsp;stamps"
+									title="Italy, Cartoons, 2005, 5&nbsp;stamps"
+									loading="lazy" />
 							</a>
 							<figcaption><a href="../series/info.html">Cartoons, 2005, 5&nbsp;stamps</a></figcaption>
 						</figure>
 						<figure>
 							<a href="../series/info.html">
-								<img src="http://via.placeholder.com/250" alt="Italy, Prehistoric animals, 22&nbsp;stamps" title="Italy, Prehistoric animals, 22&nbsp;stamps" />
+								<img src="http://via.placeholder.com/250"
+									alt="Italy, Prehistoric animals, 22&nbsp;stamps"
+									title="Italy, Prehistoric animals, 22&nbsp;stamps"
+									loading="lazy" />
 							</a>
 							<figcaption><a href="../series/info.html">Prehistoric animals, 22&nbsp;stamps</a></figcaption>
 						</figure>
 						<figure>
 							<a href="../series/info.html">
-								<img src="http://via.placeholder.com/250" alt="Italy, Prehistoric animals, 1983, 5&nbsp;stamps" title="Italy, Prehistoric animals, 1983, 5&nbsp;stamps" />
+								<img src="http://via.placeholder.com/250"
+									alt="Italy, Prehistoric animals, 1983, 5&nbsp;stamps"
+									title="Italy, Prehistoric animals, 1983, 5&nbsp;stamps"
+									loading="lazy" />
 							</a>
 							<figcaption><a href="../series/info.html">Prehistoric animals, 1983, 5&nbsp;stamps</a></figcaption>
 						</figure>
 						<figure>
 							<a href="../series/info.html">
-								<img src="http://via.placeholder.com/250" alt="Italy, Famous People, 2003, 4&nbsp;stamps" title="Italy, Famous People, 2003, 4&nbsp;stamps" />
+								<img src="http://via.placeholder.com/250"
+									alt="Italy, Famous People, 2003, 4&nbsp;stamps"
+									title="Italy, Famous People, 2003, 4&nbsp;stamps"
+									loading="lazy" />
 							</a>
 							<figcaption><a href="../series/info.html">Famous People, 2003, 4&nbsp;stamps</a></figcaption>
 						</figure>
 						<figure>
 							<a href="../series/info.html">
-								<img src="http://via.placeholder.com/250" alt="Italy, Sport, 1996, 1&nbsp;stamp" title="Italy, Sport, 1996, 1&nbsp;stamp" />
+								<img src="http://via.placeholder.com/250"
+									alt="Italy, Sport, 1996, 1&nbsp;stamp"
+									title="Italy, Sport, 1996, 1&nbsp;stamp"
+									loading="lazy" />
 							</a>
 							<figcaption><a href="../series/info.html">Sport, 1996, 1&nbsp;stamp</a></figcaption>
 						</figure>