move flutter_filament plugin to federated structure

flutter_filament_federated/flutter_filament_ffi/pubspec.yaml

@@ -0,0 +1,31 @@
+name: flutter_filament_ffi
+description: An FFI interface for the flutter_filament plugin (all platforms except web).
+repository: https://github.com/nmfisher/flutter_filament/flutter_filament
+version: 0.0.1
+
+environment:
+  sdk: ">=3.3.0 <4.0.0"
+  flutter: ">=3.0.0"
+flutter:
+  plugin:
+    implements: flutter_filament_platform_interface
+    platforms:
+      ios:
+        dartPluginClass: FlutterFilamentFFI
+      android:
+        dartPluginClass: FlutterFilamentFFI
+      macos:
+        dartPluginClass: FlutterFilamentFFI
+      windows:
+        dartPluginClass: FlutterFilamentFFI
+dependencies:
+  flutter:
+    sdk: flutter
+  plugin_platform_interface: ^2.1.0
+  flutter_filament_platform_interface:
+    path: ../flutter_filament_platform_interface
+
+dev_dependencies:
+  flutter_test:
+    sdk: flutter
+  mockito: ^5.0.0