feat(workflows-sdk,core-flows,medusa,types): add workflow to update promotions to cart (#6474)

what:

- adds API + workflow to add/remove promotions in a cart
- minor fixes in promotions module
- minor type fixes in cart module
- typing fix in workflows-sdk (Thanks @adrien2p)
- fix step result in workflows-sdk (Thanks @adrien2p)

RESOLVES CORE-1768

Co-authored-by: Adrien de Peretti <25098370+adrien2p@users.noreply.github.com>

packages/workflows-sdk/src/utils/composer/create-workflow.ts

@@ -5,7 +5,7 @@ import {
   WorkflowManager,
 } from "@medusajs/orchestration"
 import { LoadedModule, MedusaContainer } from "@medusajs/types"
-import { isString, OrchestrationUtils } from "@medusajs/utils"
+import { OrchestrationUtils, isString } from "@medusajs/utils"
 import { ExportedWorkflow, exportWorkflow } from "../../helper"
 import { proxify } from "./helpers/proxy"
 import {

packages/workflows-sdk/src/utils/composer/type.ts

@@ -42,6 +42,7 @@ export type WorkflowData<T = unknown> = (T extends object
       [Key in keyof T]: WorkflowData<T[Key]>
     }
   : T & WorkflowDataProperties<T>) &
+  T &
   WorkflowDataProperties<T> & {
     config(
       config: { name?: string } & Omit<