MID-11096 Fix missing zip suffix on tracing reports

[kay1313]

Summary

Fixes MID-11096: downloaded tracing report files were missing the .zip filename extension even though the stored report output was a ZIP archive.

The change updates ReportDownloadHelper.getReportFileName(...) so that ZIP-backed report outputs are downloaded with a .zip suffix when the display name does not already include one.

Changes

• Added ZIP filename extension handling for report downloads.
• Detects ZIP report outputs based on the stored report file path extension.
• Preserves existing .zip suffixes and avoids duplicating them.
• Keeps filename sanitization via FilenameUtils.getName(...).
• Adds regression tests for:
  • appending .zip to ZIP report downloads
  • avoiding duplicate .zip
  • leaving non-ZIP reports unchanged
  • stripping path components before appending .zip
  • handling reports without a file path
• Registered the new test class in testing-integration.xml.
• Added release note entry for MID-11096.

Testing

Added regression coverage in ReportDownloadHelperTest for ZIP suffix handling in downloaded report filenames.