fix(core-flows): complete cart improvements (#12646)

* fix(core-flows): use cartId as transactionId and acquire lock to complete cart

* fix cart update compensation

.changeset/proud-dancers-film.md

@@ -0,0 +1,7 @@
+---
+"@medusajs/workflows-sdk": patch
+"@medusajs/core-flows": patch
+"@medusajs/utils": patch
+---
+
+fix(core-flows): use cart_id to complete cart on payment webhook and lock cart before completion