API Updates for beta branch

[richardm-stripe]

Codegen for openapi v218.
cc @stripe/api-libraries

Changelog

• Updated stable APIs to the latest version
• Add support for new resource Tax.Registration
• Add support for Create, List, and Update methods on resource Registration
• Add support for Controller on AccountCreateOptions and AccountUpdateOptions
• Add support for Application and Dashboard on AccountController
• Remove support for Timestamp on QuoteLineActionsAddDiscountDiscountEnd
• Change type of QuoteLineActionsAddDiscountDiscountEndType from literal('timestamp') to literal('line_ends_at')
• Remove support for Index on QuoteLineActionsAddItemDiscounts, QuoteLineActionsRemoveDiscount, QuoteLineActionsSetDiscounts, QuoteLineActionsSetItemsDiscounts, SubscriptionSchedulePhasesAddInvoiceItemsDiscounts, SubscriptionSchedulePhasesDiscounts, and SubscriptionSchedulePhasesItemsDiscounts