[Request]: Migrate to FFI

### Plugin

battery_plus

### Use case

The packages you guys have been maintaining are crucial for the Flutter ecosystem.
Method Channels work great, but now that FFI and JNI are maturing, I think it would be a great time to start migrating over to them where possible.

The primary benefits to this are:
- Synchronous API
- Improved Performance
- Vanilla Dart Support

### Proposal

I've already migrated path_provider to use FFI (https://pub.dev/packages/path_provider_ffi) and I would love to do that here too.
Would you be interested in a PR. I would start with battery_plus first.

Inizia esaminando il plugin battery_plus e il package path_provider_ffi menzionato per comprendere l’approccio di migrazione proposto. Conferma l’ambito della sostituzione di Method Channels con FFI o JNI e definisci il completamento in base all’API sincrona richiesta, alle prestazioni migliorate e al supporto per vanilla Dart.

Scritto dal modello di indicizzazione a partire dal testo della issue.