feat: add no NAS failure reason and refactor Synology extension exception handling

[simonxander]

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.

[mengyushen]

It looks like the standard exception classes already cover the scenarios we are handling. Would you mind replacing SynologyException with standard exceptions?

It would be great to avoid introducing custom exceptions if we don't strictly need them.

[mengyushen]

Thanks for making the switch to standard exceptions. I appreciate the update!