fix(usb): notify HID handler on bus reset

[srpatcha]

Summary

• add a backward-compatible HID request-handler reset callback
• notify the handler after a USB bus reset while clearing partial report state
• cover handler state restoration and the no-handler path with unit tests

Fixes #6891

Testing

• Windows-equivalent repository formatting passed
• git diff --check passed
• Rust tests could not be run locally because no Rust toolchain is installed on the host