Use updateItem mutations

[sirugh]

Description

Updates the cartOptions to use the updateCartItems mutation for simple products.
As there is no update mutation for configurable products we just remove then add the new configuration in place of a singular update call.
I also added some logic to disable the Update Cart button until either the quantity or the options have been touched.

Related Issue

Closes PWA-143.

Acceptance

Verification Stakeholders

Specification

Verification Steps

Simple product

1. Add a simple product to the cart.
2. Open the edit form. The update button should be disabled.
3. Change the quantity. The update button should enable.
4. Click the update button. The product should update in the cart.

Configurable product

1. Add a configurable product to cart.
2. Open the edit form. The update button should be disabled.
3. Change the quantity. The update button should enable.
4. Click the update button. The product should update in the cart.
5. Open the edit form. The update button should be disabled.
6. Change an option like color or size. The update button should enable.
7. Click the update button. The product should update in the cart.

Screenshots / Screen Captures (if appropriate)

Checklist

• I have updated the documentation accordingly, if necessary.
• I have added tests to cover my changes, if necessary.

[PWAStudioBot]

	Messages
📖	Access a deployed version of this PR here. Make sure to wait for the "pwa-pull-request-deploy" job to complete.
📖	DangerCI Failures related to missing labels/description/linked issues/etc will persist until the next push or next nightly build run (assuming they are fixed).
📖	Associated JIRA tickets: PWA-143.

Generated by 🚫 dangerJS against 6eebf9d

[tjwiebell]

Looks good, just a question about preventing that double render on update.

[tjwiebell]

Looks good with loading indicator fix, nice work!

[tjwiebell]

Even better now 👍