`PurchasesOrchestrator`: replaced manual `Lock` with `Atomic` (#1664)
`PurchasesOrchestrator`: replaced manual `Lock` with `Atomic` (#1664)

See #983. This is less error-prone as it's impossible to have deadlocks, or to access the data without locking (like we were doing in some cases).
Also, this approach has 2 separate locks for each property, so unrelated accesses won't lock each other now.
RevenueCat/purchases-ios,RevenueCat/purchases-ios,RevenueCat/purchases-ios,RevenueCat/purchases-ios,RevenueCat/purchases-ios