Request: Update stripe webhook to update subscriptions when they are changed on Stripe

[eashaw]

This request is expected to be doable in ≤1 sprint. It would be valuable even if nothing else ships.

It will be reviewed by the acting PM for the #g-website product group, and then hopefully prioritized, drafted, and implemented.

Goal

User story
As a Fleet team member,
I want to only update a Fleet Premium subscription in the Stripe UI
so that I make the process of updating license dispenser subscriptions easier.

For help creating a user story, see "Writing a good user story" in the website handbook.

Changes

This issue's estimation includes completing the following:

• [ ] Update the receive-from-stripe webhook to update the number of hosts and subscription price on a subscription record when it receives a customer.subscription.updated events
• [ ] Update the receive-from-stripe webhook to generate new license keys for subscriptions when it receives a invoice.paid event that have subscription_update as the billing_reason

QA

The testing steps outlined below must be verified before the associated PR is merged. See "Quality" in the website handbook for help.

Manual testing steps

1. Step 1
2. Step 2
3. Step 3

In addition to the steps above, ensure changes have been checked at all breakpoints, and a browser compatibility test has been carried out on supported browsers.

Testing notes

[mikermcneil]

@Patagonia121 once we have a handbook responsibilitiy merged on /handbook/customer-success for "Increase a self-service customer's host count", this can be considered closed

[fleet-release]

Stripe webhook shifts, Subscriptions in cloud sync, Effortless updates flow.