Describe the bug
I'm trying to use the addFee mutation in order to add extra fees in the checkout page when a user select some optional services. The problem is that it doesn't add the fee to the cart.

To Reproduce
Steps to reproduce the behavior:

1. Execute the following mutation (i'm using the GraphQL IDE):

mutation addFee {
  addFee(input: {name: "Extra service", amount: 1.5}) {
    clientMutationId
    cart {
      fees {
        name
        amount
      }
    }
  }
}

Expected behavior
Although the mutation result returns this:

"data": {
    "addFee": {
      "clientMutationId": null,
      "cart": {
        "fees": [
          {
            "name": "Extra service",
            "amount": 1.5
          }
        ]
      }
    }
  }

if I visit the cart page I can't see the fees being applied:

Desktop (please complete the following information):

• OS: macOS
• Browser Chrome

Plugin Versions

• WooGraphQL Version: 0.8.1
• WPGraphQL Version: 1.3.5
• WordPress Version: 5.7.1
• WooCommerce Version: 5.2.2