rework trashed assets handling

- add new table trashed_local_asset
- mirror trashed assets data in trashed_local_asset.
- compute checksums for assets trashed out-of-app.
- restore assets present in trashed_local_asset and non-trashed in remote_asset.
- simplify moving-to-trash logic based on remote_asset events.

mobile/lib/domain/models/asset/trashed_asset.model.dart

@@ -0,0 +1,76 @@
+import 'package:immich_mobile/domain/models/asset/base_asset.model.dart';
+
+class TrashedAsset {
+  final String id;
+  final String name;
+  final String albumId;
+  final String? checksum;
+  final AssetType type;
+  final DateTime createdAt;
+  final DateTime updatedAt;
+  final int? size;
+
+  const TrashedAsset({
+    required this.id,
+    required this.name,
+    required this.checksum,
+    required this.albumId,
+    required this.type,
+    required this.createdAt,
+    required this.updatedAt,
+    this.size,
+  });
+
+  TrashedAsset copyWith({
+    String? id,
+    String? name,
+    String? albumId,
+    String? checksum,
+    AssetType? type,
+    DateTime? createdAt,
+    DateTime? updatedAt,
+    int? size,
+  }) {
+    return TrashedAsset(
+      id: id ?? this.id,
+      name: name ?? this.name,
+      albumId: albumId ?? this.albumId,
+      checksum: checksum ?? this.checksum,
+      type: type ?? this.type,
+      createdAt: createdAt ?? this.createdAt,
+      updatedAt: updatedAt ?? this.updatedAt,
+      size: size ?? this.size,
+    );
+  }
+
+  @override
+  String toString() {
+    return 'TrashedAsset('
+        'id: $id, '
+        'name: $name, '
+        'albumId: $albumId, '
+        'checksum: $checksum, '
+        'type: $type, '
+        'createdAt: $createdAt, '
+        'updatedAt: $updatedAt, '
+        'size: ${size ?? "<NA>"}'
+        ')';
+  }
+
+  @override
+  bool operator ==(Object other) =>
+      identical(this, other) ||
+      other is TrashedAsset &&
+          runtimeType == other.runtimeType &&
+          id == other.id &&
+          name == other.name &&
+          albumId == other.albumId &&
+          checksum == other.checksum &&
+          type == other.type &&
+          createdAt == other.createdAt &&
+          updatedAt == other.updatedAt &&
+          size == other.size;
+
+  @override
+  int get hashCode => Object.hash(id, name, albumId, checksum, type, createdAt, updatedAt, size);
+}