MOB-76 Update logic for exporting copies for JS

[pankajvaghela]

Update logic for exporting copies for JS

Before copies were exported as 1-on-1 mapping like :

{
  "Basket.EditBasket.AddToDeliveryCurrentDeliverySection.Subtitle.COPY": "%1$s Produkte",
   //...
}

With this change, copies will be exported as JSON object :

{
  "Basket": {
    "EditBasket": {
      "AddToDeliveryCurrentDeliverySection": {
        "Subtitle": {
          "COPY": "%1$s Produkt"
        },
     }
   }
}

JIRA Ticket : https://picnic.atlassian.net/browse/MOB-76