Add Tryton synchronization for CatalogSale

- Add external_id field to CatalogSale model for tracking synced sales
- Create migration 0047 for external_id field
- Add TrytonCatalogSale and TrytonCatalogSaleLine classes for Tryton RPC format
- Add send_catalog_sales_to_tryton() method to SaleTrytonService
- Create CatalogSalesToTrytonView API endpoint (POST)
- Register endpoint at /don_confiao/api/enviar_catalog_sales_a_tryton
- Add test for external_id field functionality
- Catalog sales sync to same Tryton model as Sale (model.sale.sale.create)
- Differentiated by reference 'don_confiao_catalog X' and description 'Venta de catálogo'
- Filters only catalog sales without external_id to avoid duplicates

tienda_ilusion/don_confiao/migrations/0047_catalogsale_external_id.py

@@ -0,0 +1,18 @@
+# Generated by Django 5.0.6 on 2026-05-31 01:46
+
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('don_confiao', '0046_product_active'),
+    ]
+
+    operations = [
+        migrations.AddField(
+            model_name='catalogsale',
+            name='external_id',
+            field=models.CharField(blank=True, max_length=100, null=True),
+        ),
+    ]