feat: allow html content for notifications (#9613)

* feat: allow passing provider specific metadata to notification module

* changed providerContext to snake cased

* rename provider_context to content

packages/modules/notification/integration-tests/__tests__/notification-module-service/index.spec.ts

@@ -85,6 +85,30 @@ moduleIntegrationTestRunner<INotificationModuleService>({
         )
       })
 
+      it("should send a notification and don't store the content in the database", async () => {
+        const notification = {
+          to: "admin@medusa.com",
+          template: "signup-template",
+          channel: "email",
+          data: {},
+          content: {
+            html: "<p>Welcome to medusa</p>",
+          },
+        }
+
+        const result = await service.createNotifications(notification)
+        const dbEntry = await service.retrieveNotification(result.id)
+
+        expect(dbEntry).toEqual(
+          expect.objectContaining({
+            provider_id: "test-provider",
+            external_id: "external_id",
+            status: NotificationStatus.SUCCESS,
+          })
+        )
+        expect(dbEntry).not.toHaveProperty("content")
+      })
+
       it("should emit an event when a notification is created", async () => {
         const notification = {
           to: "admin@medusa.com",