TF-548 Create abstract AutoCompleteDataSource common to all

model/lib/autocomplete/auto_complete_pattern.dart

@@ -0,0 +1,20 @@
+
+import 'package:equatable/equatable.dart';
+import 'package:jmap_dart_client/jmap/account_id.dart';
+
+class AutoCompletePattern with EquatableMixin {
+
+  final String word;
+  final int? limit;
+  final AccountId? accountId;
+
+  AutoCompletePattern({
+    required this.word,
+    this.limit,
+    this.accountId,
+  });
+
+  @override
+  List<Object?> get props => [word, limit, accountId];
+
+}