Identify cart lines by `view_key` in `cartLinesUpdate` and `cartLinesRemove`

You can now identify cart lines by their view_key when calling the cartLinesUpdate and cartLinesRemove mutations, as an alternative to the cart line id.

What's new

• cartLinesUpdate accepts a viewKey on each CartLineUpdateInput, mutually exclusive with id.
• cartLinesRemove accepts a viewKeys list, mutually exclusive with lineIds.

How to use

Provide exactly one identifier per line. Existing integrations that use id or lineIds keep working with no changes.

mutation RemoveLineByViewKey($cartId: ID!) {
  cartLinesRemove(cartId: $cartId, viewKeys: ["794864053:7c2a9f..."]) {
    cart { id }
    userErrors { field message }
  }
}