Add the ability to dispatch custom events to the document object

[marcomontalbano]

With this PR, Commerce Layer drop-in.js will be able to dispatch the following custom events to the document object.

All custom events implement the same interface; request.args and response vary from one event to another.

interface CLCustomEvent {
  request: {
    args: [ arg1: any, arg2: any, ... ]
  }
  response: any
}

Event types

cl.cart.addItem

This event is dispatched when an item is added to cart.

• request.args [sku: string, quantity: number]
• response LineItem

document.addEventListener('cl.cart.addItem', (event) => {
  console.info(event.detail)
})

cl.prices.getPrice

This event is dispatched whenever a price is fetched.

• request.args [code: string]
• response Price

document.addEventListener('cl.prices.getPrice', (event) => {
  console.info(event.detail)
})

cl.skus.getSku

This event is dispatched whenever a SKU is fetched.

• request.args [code: string]
• response Sku

document.addEventListener('cl.skus.getSku', (event) => {
  console.info(event.detail)
})

cl-customevent.mp4