feat: add NO_NAS_IN_ACCOUNT failure reason and refactor Synology extension exception handling (#1480)

Changes:

Core SPI Updates
   * New Failure Reason: Added NO_NAS_IN_ACCOUNT to FailureReasons enum.
* New Exception: Created NoNasInAccountException in the SPI to handle
cases where the destination account lacks a
     NAS setup.

Synology Extension Refactoring
* Exception Standardization: Removed custom Synology exception classes
(e.g., SynologyException,
SynologyImportException, SynologyErrorCode) and replaced them with
standard SPI exceptions:
* SynologyImportException -> UploadErrorException for general errors
   * Enhanced Error Handling:
       * HTTP 413: Now throws DestinationMemoryFullException.
* HTTP 422: Checks specific Synology error codes (2000, 2001) and throws
NoNasInAccountException.
* Code Cleanup: Updated SynologyMediaImporter, SynologyPhotosImporter,
and SynologyVideosImporter to directly re-throw exceptions for the
framework to handle, rather than catching them and returning failure
results.
   * Avoid using lambda function for checked exception
       * Replace `forEach()` by for-loop
* Replace atomic `readyAlbumMap.compute()` by synchronized lock
protected map operations

 Testing
* Updated all Synology unit tests to assert against the new SPI
exceptions.
* Added specific test cases to verify handling of HTTP 413 and 422
response codes.

Author: simonxander

extensions/data-transfer/portability-data-transfer-synology/src/main/java/org/datatransferproject/datatransfer/synology/constant/SynologyErrorCode.java

@@ -41,7 +41,7 @@ public ImportResult importItem(
       synologyUploader.importVideos(data.getVideos(), jobId);
     } catch (Exception e) {
       monitor.severe(() -> "[SynologyImporter] SynologyMediaImporter failed to import data:" + e);
-      return new ImportResult(e);
+      throw e;
     }
 
     return ImportResult.OK;

extensions/data-transfer/portability-data-transfer-synology/src/main/java/org/datatransferproject/datatransfer/synology/exceptions/SynologyException.java

@@ -40,7 +40,7 @@ public ImportResult importItem(
       synologyUploader.importPhotos(data.getPhotos(), jobId);
     } catch (Exception e) {
       monitor.severe(() -> "[SynologyImporter] SynologyPhotosImporter failed to import data:" + e);
-      return new ImportResult(e);
+      throw e;
     }
 
     return ImportResult.OK;