added cache for categories

lib/tables/ref_manufacturers.dart

@@ -0,0 +1,41 @@
+import 'package:supabase_flutter/supabase_flutter.dart';
+import 'package:uuid/uuid.dart';
+
+class RefManufacturers {
+  final SupabaseClient _supabase = Supabase.instance.client;
+
+  Future<List> getList() async {
+    try {
+      final data = await _supabase
+          .from('ref_manufacturers')
+          .select('manufacturer_name')
+          .order('manufacturer_name', ascending: true);
+      return data.toList();
+    } catch (e) {
+      return [];
+    }
+  }
+
+  Future<String> getUUID(String name) async {
+    try {
+      final data =
+          await _supabase.from('ref_manufacturers').select('ref_manufacturers_uuid').eq('manufacturer_name', name);
+      return data.first['ref_manufacturers_uuid'].toString();
+    } catch (e) {
+      return '';
+    }
+  }
+
+  Future<bool> postManufacturer(String name, String address) async {
+    try {
+      final genericUUID = Uuid().v4();
+
+      await _supabase
+          .from('ref_manufacturers')
+          .insert({'ref_manufacturers_uuid': genericUUID, 'manufacturer_name': name, 'manufacturer_address': address});
+      return true;
+    } catch (e) {
+      return false;
+    }
+  }
+}