slapos_panel: try not to duplicate software product

master/bt5/slapos_panel/SkinTemplateItem/portal_skins/slapos_panel/Project_addSlapOSSoftwareProduct.py

@@ -2,6 +2,18 @@ from Products.ERP5Type.Message import translateString
 
 portal = context.getPortalObject()
 
+# First, search if the release already exists
+software_release_variation = portal.portal_catalog.getResultValue(
+  portal_type="Software Product Release Variation",
+  url_string=software_release,
+)
+if software_release_variation is not None:
+  return software_release_variation.getParentValue().Base_redirect(
+    keep_items={
+      'portal_status_message': translateString('Software Product already exist.')
+    }
+  )
+
 software_product = portal.software_product_module.newContent(
   title=title,
   follow_up_value=context