FastbootGui Version 0.2

** Problem with the Browser feature on Windows: the script will shut down because a module called "win32timezone" is missing. I need to find a way to fix this.

Updates :

1. Assignment of the "selected_file" attribute
   The attribute is now initialized in the constructor (self.selected_file = None) to prevent assignment errors.

2. Error handling when checking adb/fastboot commands
   In the update_device_status method, exceptions (notably FileNotFoundError) are handled to prevent the application from crashing.

3. Full translation into English
   All text strings have been translated into English by default (with the option to switch to French via the language toggle).

4. Multi-threading and real-time feedback
   All long-running operations (download, extraction, installation, update, flash, etc.) run in separate threads to ensure UI responsiveness. A label at the bottom displays the real-time status of the devices.

5. Adding an automatic detection feature (in a loop), which attempts to detect your device via adb/fastboot.