fix: 🐛 error on select after insert

Always return inserted record(s) as list with response

Fixes #16

Author: jwelmac

lib/src/mock_supabase_http_client.dart

@@ -338,9 +338,10 @@ class MockSupabaseHttpClient extends BaseClient {
     if (!_database.containsKey(tableKey)) {
       _database[tableKey] = [];
     }
+
     if (data is Map<String, dynamic>) {
       _database[tableKey]!.add(data);
-      return _createResponse(data, request: request);
+      return _createResponse([data], request: request);
     } else if (data is List) {
       final List<Map<String, dynamic>> items =
           List<Map<String, dynamic>>.from(data);

test/mock_supabase_http_client_test.dart

@@ -35,6 +35,15 @@ void main() {
       expect(posts.first, {'title': 'Hello, world!'});
     });
 
+    test('Insert then select', () async {
+      // Test inserting a record
+      final posts = await mockSupabase
+          .from('posts')
+          .insert({'title': 'Hello, world!'}).select();
+      expect(posts.length, 1);
+      expect(posts.first, {'title': 'Hello, world!'});
+    });
+
     test('Upsert', () async {
       // Test upserting a record
       await mockSupabase