Added a new workbook for WatchGuard Firebox

[samikroy]

This workbook contains the following

• Event Severity Analysis – Breakdown of events by severity levels (Info, Debug, Error, Warning, Other).
• Event Outcomes – Success vs Failure distribution and result breakdown.
• Firewall Actions – Allow vs Deny traffic visualized.
• Event Volume Trends – Hourly event trends and long-term time series.
• Admin Activity – Top admin users by event count.
• Policy Insights – Most triggered firewall policies and top policy actions.
• Top blocked destination IPs
• Frequent message IDs
• Success vs failure trends over time