Update expected-lite to v0.9.0

* Update expected-lite to v0.9.0
  https://github.com/nonstd-lite/expected-lite/releases/tag/v0.9.0
* Add error messages for various RSS processing error
* Preserve CRLF endings for expected-lite
  So that we can verify the hash matches upstream easily.

PR #23440.
Closes #22950.

.gitattributes

@@ -8,3 +8,6 @@ core.eol=lf
 
 dist/windows/license.txt text eol=crlf
 test/testdata/crlf.txt text eol=crlf
+
+# disable line endings conversions
+src/base/3rdparty/expected.hpp -text

.pre-commit-config.yaml

@@ -39,6 +39,7 @@ repos:
       args: ["--fix=lf"]
       exclude: |
         (?x)^(
+          src/base/3rdparty/expected.hpp |
           src/webui/www/private/css/lib/.* |
           src/webui/www/private/scripts/lib/.* |
           dist/windows/license.txt |

src/base/rss/rss_session.cpp

@@ -405,12 +405,16 @@ void Session::loadLegacy()
         const QString feedUrl = Item::relativeName(legacyPath);
 
         for (const QString &folderPath : asConst(Item::expandPath(parentFolderPath)))
-            addFolder(folderPath);
+        {
+            if (const auto result = addFolder(folderPath); !result)
+                LogMsg(tr("Failed to add RSS folder item. Reason: \"%1\"").arg(result.error()), Log::WARNING);
+        }
 
         const QString feedPath = feedAliases[i].isEmpty()
                 ? legacyPath
                 : Item::joinPath(parentFolderPath, feedAliases[i]);
-        addFeed(feedUrl, feedPath);
+        if (const auto result = addFeed(feedUrl, feedPath); !result)
+            LogMsg(tr("Failed to add RSS feed item. Reason: \"%1\"").arg(result.error()), Log::WARNING);
         ++i;
     }
 }