feat(ui): Add last validation time, disable revalidation if PR not open

• feat(ui): Add last validation time, disable revalidation if PR not open

In the status UI, previously we never stated when the last validation occurred. As we have access to this data, we should tell the user when the last validation of a commit associated with a PR happened. This better supports users to know if their failure may be due to out of date validation.

Additionally, in the case of GH PRs where we have logic to manage those calls separately, we can now check if the PR is open. We use this to now toggle whether the revalidation button will be usable and whether the hCaptcha is injected.

src/main/java/org/eclipsefoundation/git/eca/config/EclipseQuteTemplateExtensions.java

@@ -11,6 +11,7 @@
 **********************************************************************/
 package org.eclipsefoundation.git.eca.config;
 
+import java.time.format.DateTimeFormatter;
 import java.util.List;
 
 import org.apache.commons.lang3.StringUtils;
@@ -49,6 +50,24 @@ public class EclipseQuteTemplateExtensions {
         return statuses.stream().flatMap(s -> s.getErrors().stream()).toList();
     }
 
+    /**
+     * Sorts list and retrieves the most recently modified status, and returns a human readable format of the time.
+     * 
+     * @param statuses a list of commit validation statuses to retrieve a modification time from
+     * @return the most recent modification time for any of the passed statuses.
+     */
+    static String getLastKnownValidationTime(List<CommitValidationStatus> statuses) {
+        CommitValidationStatus latestStatus = statuses
+                .stream()
+                .sorted((o1, o2) -> o2.getLastModified().compareTo(o1.getLastModified()))
+                .findFirst()
+                .orElse(null);
+        if (latestStatus == null) {
+            return "Unknown";
+        }
+        return latestStatus.getLastModified().format(DateTimeFormatter.RFC_1123_DATE_TIME);
+    }
+
     /**
      * Converts the status list to a list of email addresses that were associated with validated commits.
      *