* Rename `RecurlyWrapper` to `promises`, as it will only contain the promises soon
* Update `apiRequest`
* Update `_parseXml`
* Update `_parseXmlAndGetAttribute`
* Update `_parse*Xml`
* Update `updateAccountEmailAddress`
* Update `checkAccountExists`
* Update `createAccount`
* Update `createBillingInfo`
* Update `setAddressAndCompanyBillingInfo`
* Update `createSubscription`
* Update `_createPaypalSubscription`
* Update `_handle422Response`
* Update `_createCreditCardSubscription`
* Update `createSubscription`
* Update `getSubscriptions`
* Update `getSubscription`
* Update `getPaginatedEndpoint`
* Update `getAccount`
* Update `getAccountActiveCoupons`
* Update `getCoupon`
* Update `getBillingInfo`
* Update `getAccountPastDueInvoices`
* Update `attemptInvoiceCollection`
* Update `updateSubscription`
* Update `createFixedAmmountCoupon`
* Update `lookupCoupon`
* Update `redeemCoupon`
* Update `extendTrial`
* Update `listAccountActiveSubscriptions`
* To find which functions to add as callbackified, I used this Regex:
`RecurlyWrapper\.(?!promises)[^.\s]*`
And after adding callbackified functions, we're left with no results with the Regex:
`RecurlyWrapper\.(?!promises|apiUrl|_buildXml|_parseXml|attemptInvoiceCollection|createFixedAmmountCoupon|getAccountActiveCoupons|getBillingInfo|getPaginatedEndpoint|getSubscription|updateAccountEmailAddress)[^.\s]*`
* Update unit tests
* Test `getSubscription` both as "promise" and as "callback"
I'm not sure if we want to generalize this.
* Fix: add missing `await`s (!!)
* Change `apiRequest` to reject errors instead of resolving it in an object
* Fixup for CollectPayPalPastDueInvoice test
* Fix: callbackify `getSubscriptions` (!!)
* Replace `.then(...)` chain by multiple `await`
* Fixup `attemptInvoicesCollection`: prevent reading length of undefined
* Use `return await` when returning promises
Per https://github.com/overleaf/internal/pull/18384#pullrequestreview-2065738771
GitOrigin-RevId: ceda755b24fd29f97a27e60ac5db9bc7e369f932
