Add a "Updating Billing Information and Payment Method" section to the
Plans & Billing page covering the path from Settings > Plans & Billing >
Manage Plan into the Stripe billing portal, where users can change their
payment method and use "Update information" to edit company name, billing
address, billing email, and tax information.
Note that this is NetBird Cloud specific functionality — self-hosted
deployments are not billed through the Stripe billing portal.
