fix(medusa): Handle variant error during line item generation (#5145)

* fix(medusa): Handle variant error during line item generation

* improve and tests

* cleanup

* update messages

* Create few-masks-draw.md

* change error type

* fix unit tests

.changeset/few-masks-draw.md

@@ -0,0 +1,5 @@
+---
+"@medusajs/medusa": patch
+---
+
+fix(medusa): Handle variant error during line item generation