feat: add UNCHANGED state handling in SettingsServiceBean operations #11639

- Introduced `UNCHANGED` as a new operation type for settings.
- Updated `convertToJson` method to include unchanged settings in JSON output.
- Enhanced `replaceAllSettings` logic to track unchanged settings when content remains identical.
- The reason for this is idempotency: if nothing changed, nothing should be done. Replacing the present content of an existing setting is unnecessary, wasting CPU cycles, and we also want the admin to be informed about what actually is getting changed. Before, all of these unchanged elements would be counted as "updated".

Author: poikilotherm

src/main/java/edu/harvard/iq/dataverse/settings/SettingsServiceBean.java

@@ -1191,28 +1191,32 @@ static Set<Setting> convertJsonToSettings(JsonObject settings) {
     static enum Op {
         UPDATED,
         CREATED,
-        DELETED;
+        DELETED,
+        UNCHANGED;
 
         static JsonObjectBuilder convertToJson(Map<Setting, Op> operationalDetails) {
             // Create a nice represenation of what happened as Json
             JsonObjectBuilder jbo = Json.createObjectBuilder();
             JsonArrayBuilder created = Json.createArrayBuilder();
             JsonArrayBuilder updated = Json.createArrayBuilder();
             JsonArrayBuilder deleted = Json.createArrayBuilder();
+            JsonArrayBuilder unchanged = Json.createArrayBuilder();
 
             operationalDetails.forEach((setting, op) -> {
                 String name = convertToJsonKey(setting);
                 switch (op) {
                     case CREATED -> created.add(name);
                     case UPDATED -> updated.add(name);
                     case DELETED -> deleted.add(name);
+                    case UNCHANGED -> unchanged.add(name);
                 }
             });
 
             return jbo
                 .add("created", created)
                 .add("updated", updated)
-                .add("deleted", deleted);
+                .add("deleted", deleted)
+                .add("unchanged", unchanged);
         }
     }
 
@@ -1268,10 +1272,14 @@ public Map<Setting, Op> replaceAllSettings(Set<Setting> newSettings) {
             // Setting exists in both - update with new values
             } else {
                 Setting newSetting = newByKey.get(key);
-                // We use the already managed entity and update it with the content of the new setting.
-                // (This means we don't need to call em.merge(), the ORM will track and execute it for us.)
-                existingSetting.setContent(newSetting.getContent());
-                opsTracking.put(existingSetting, Op.UPDATED);
+                if (existingSetting.getContent().equals(newSetting.getContent())) {
+                    opsTracking.put(existingSetting, Op.UNCHANGED);
+                } else {
+                    // We use the already managed entity and update it with the content of the new setting.
+                    // (This means we don't need to call em.merge(), the ORM will track and execute it for us.)
+                    existingSetting.setContent(newSetting.getContent());
+                    opsTracking.put(existingSetting, Op.UPDATED);
+                }
             }
         }