KM-17457: Report IAP KPI metrics for login-with-receipt

The login-with-receipt path verifies an IAP receipt against Kape but
emitted no IAP processing events. It is reached from the iOS restore
flow, the iOS login screen and tvOS login, so those verifications went
unreported.

Emit purchase/success/failure around the token(receipt:) call using the
existing event set and the .signup origin, matching how the signup
login-with-receipt fallback already reports the same verification.

Author: kp-diego-trevisan

LocalPackages/PIALibrary/Sources/PIALibrary/Account/DefaultAccountProvider.swift

@@ -177,11 +177,14 @@ public final class DefaultAccountProvider: AccountProvider, ConfigurationAccess,
 
         Task { @MainActor in
             let credentials = Credentials(username: "", password: "")
+            ServiceQualityManager.shared.iapProcessingPurchaseEvent(origin: .signup)
 
             do {
                 try await webServices.token(receipt: receiptRequest.receipt)
+                ServiceQualityManager.shared.iapProcessingSuccessEvent(origin: .signup)
                 self.handleLoginResult(error: nil, credentials: credentials, callback: callback)
             } catch {
+                ServiceQualityManager.shared.iapProcessingFailureEvent(origin: .signup, error: error)
                 self.handleLoginResult(error: error, credentials: credentials, callback: callback)
             }
         }