If waiting for push device details and got them persisted, re-emit them.

[tcard]

While once #966 is fixed new apps won't get into that "illegal"
persisted state, we still need to recover from it for old apps.

This also serves as a workaround, so that the "proper" fix for #966 is
not urgent.

[tcard]

It seems this broke some tests:

11:53:57]: ▸     ✗ Activation_state_machine__State_NotActivated__on_Event_CalledActivate__if_the_local_device_has_id_and_deviceIdentityToken_then_should_transition_to_WaitingForNewPushDeviceDetails, Test crashed

[11:53:57]: ▸     ✗ Activation_state_machine__State_WaitingForPushDeviceDetails__on_Event_GotPushDeviceDetails__should_use_custom_registerCallback_and_fire_GotDeviceRegistration_event, failed: caught "ARTPushRegistererDelegate must be implemented on AppDelegate"

[11:53:57]: ▸     ✗ Activation_state_machine__State_WaitingForPushDeviceDetails__on_Event_GotPushDeviceDetails__should_use_custom_registerCallback_and_fire_GettingDeviceRegistrationFailed_event, failed: caught "ARTPushRegistererDelegate must be implemented on AppDelegate"

[11:53:57]: ▸     ✗ Activation_state_machine__State_WaitingForPushDeviceDetails__on_Event_GotPushDeviceDetails__should_fire_GotDeviceRegistration_event, failed: caught "ARTPushRegistererDelegate must be implemented on AppDelegate"

[11:53:57]: ▸     ✗ Activation_state_machine__State_WaitingForPushDeviceDetails__on_Event_GotPushDeviceDetails__should_fire_GettingDeviceRegistrationFailed_event, failed: caught "ARTPushRegistererDelegate must be implemented on AppDelegate"

[11:53:57]: ▸     ✗ Activation_state_machine__State_WaitingForPushDeviceDetails__on_Event_GotPushDeviceDetails__should_transition_to_WaitingForDeviceRegistration, failed: caught "ARTPushRegistererDelegate must be implemented on AppDelegate"

[11:53:57]: ▸     ✗ Channel_Subscriptions__removeWhere__should_remove_by_deviceId, expected to contain <<ARTPushChannelSubscription: 0x7ffe8aa38170> -deviceId: deviceDetails2ClientA; clientId: (null);channel: pushenabled:foo;, <ARTPushChannelSubscription: 0x7ffe8aa38300> -deviceId: deviceDetails2ClientA; clientId: (null);channel: pushenabled:bar;>, got <[]>