feat: Custom line items (#10408)

* feat: Custom line items

* fix tests

* fix migration

* Allow custom items in update line item workflow

* throw if line item doesn't have a price

* minor things

* wip

* fix flows

* fix test

* add default

* add to type

packages/modules/cart/src/migrations/.snapshot-medusa-cart.json

@@ -617,6 +617,16 @@
           "default": "false",
           "mappedType": "boolean"
         },
+        "is_custom_price": {
+          "name": "is_custom_price",
+          "type": "boolean",
+          "unsigned": false,
+          "autoincrement": false,
+          "primary": false,
+          "nullable": false,
+          "default": "false",
+          "mappedType": "boolean"
+        },
         "compare_at_unit_price": {
           "name": "compare_at_unit_price",
           "type": "numeric",

packages/modules/cart/src/migrations/Migration20241218091938.ts

@@ -0,0 +1,13 @@
+import { Migration } from '@mikro-orm/migrations';
+
+export class Migration20241218091938 extends Migration {
+
+  async up(): Promise<void> {
+    this.addSql('alter table if exists "cart_line_item" add column if not exists "is_custom_price" boolean not null default false;');
+  }
+
+  async down(): Promise<void> {
+    this.addSql('alter table if exists "cart_line_item" drop column if exists "is_custom_price";');
+  }
+
+}