Feature Request: Display Per-Session Download/Upload Statistics

Issue Description

Currently, Tixati does not display download (DL) and upload (UL) statistics for the *current session*. Only lifetime totals are shown in the bytes counter. This makes it impossible to track data usage within a single session, which is critical for users on metered connections with Fair Usage Policy (FUP) limits.

Use Case

On FUP-limited connections, users need to monitor exactly how much data (in GB) has been transferred *during the current Tixati session*. The lifetime counter is insufficient, especially when Tixati runs in the background—users often close the application without noting session-specific usage.

Requested Feature  

Please add per-session DL/UL statistics (in GB, reset on application close/restart), displayed prominently, such as:  
- In the status bar (similar to Tribler's, qBittorrent’s bottom bar), or  
- In a dedicated Statistics tab (similar to BiglyBT).  

This small addition would greatly benefit users managing data caps under FUP restrictions.

Thank you for considering this improvement.