feat: Create cart with line items (#6449)

**What**
- Add support for creating a cart with items
- Add endpoint `POST /store/carts/:id/line-items`
- Add `CreateCartWorkflow`
- Add `AddToCartWorkflow`
- Add steps for both workflows

**Testing**
- Endpoints
- Workflows

I would still call this a first iteration, as we are missing a few pieces of the full flow, such as payment sessions, discounts, and taxes.

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

packages/workflow-engine-inmemory/src/utils/workflow-orchestrator-storage.ts

@@ -55,7 +55,7 @@ export class InMemoryDistributedTransactionStorage extends DistributedTransactio
     ])
   }
 
-  private stringifyWithSymbol(key, value) {
+  /*private stringifyWithSymbol(key, value) {
     if (key === "__type" && typeof value === "symbol") {
       return Symbol.keyFor(value)
     }
@@ -69,7 +69,7 @@ export class InMemoryDistributedTransactionStorage extends DistributedTransactio
     }
 
     return value
-  }
+  }*/
 
   async get(key: string): Promise<TransactionCheckpoint | undefined> {
     return this.storage.get(key)
@@ -105,7 +105,7 @@ export class InMemoryDistributedTransactionStorage extends DistributedTransactio
       })
     }
 
-    const stringifiedData = JSON.stringify(data, this.stringifyWithSymbol)
+    const stringifiedData = JSON.stringify(data)
     const parsedData = JSON.parse(stringifiedData)
 
     if (hasFinished && !retentionTime) {