bring in database

switch to just using source models (no extra db fields)
start re-implementing sync service

test/util/database.dart

@@ -0,0 +1,10 @@
+import 'package:drift/drift.dart';
+import 'package:drift/native.dart';
+import 'package:subtracks/database/database.dart';
+
+SubtracksDatabase testDatabase() => SubtracksDatabase(
+  DatabaseConnection(
+    NativeDatabase.memory(),
+    closeStreamsSynchronously: true,
+  ),
+);

test/util/http.dart

@@ -0,0 +1,6 @@
+import 'package:http/http.dart';
+
+class TestHttpClient extends BaseClient {
+  @override
+  Future<StreamedResponse> send(BaseRequest request) => request.send();
+}

test/util/subsonic.dart

@@ -0,0 +1,34 @@
+import 'package:subtracks/sources/subsonic/client.dart';
+import 'package:test/test.dart';
+
+import 'http.dart';
+
+enum Servers {
+  navidrome,
+  gonic,
+}
+
+Map<Servers, SubsonicClient> testServerClients() => {
+  Servers.navidrome: SubsonicClient(
+    http: TestHttpClient(),
+    address: Uri.parse('http://localhost:4533/'),
+    username: 'admin',
+    password: 'password',
+  ),
+  Servers.gonic: SubsonicClient(
+    http: TestHttpClient(),
+    address: Uri.parse('http://localhost:4747/'),
+    username: 'admin',
+    password: 'admin',
+  ),
+};
+
+void groupByTestServer(void Function(SubsonicClient client) callback) {
+  final clients = testServerClients();
+
+  for (final MapEntry(key: server, value: client) in clients.entries) {
+    group(server.name, () {
+      callback(client);
+    });
+  }
+}