service/am: Implement friend invitation storage channel

Implements TryPopFromFriendInvitationStorageChannel to properly handle
friend invitation data storage and retrieval. This includes:

- Add ResultNoData error code to am_results.h
- Add friend_invitation_storage_channel storage queue to Applet struct
- Implement proper data handling in TryPopFromFriendInvitationStorageChannel

The implementation now properly manages a queue of friend invitation data
and returns appropriate results based on data availability.

src/core/hle/service/am/am_results.h

@@ -13,5 +13,6 @@ constexpr Result ResultLibraryAppletTerminated{ErrorModule::AM, 22};
 constexpr Result ResultInvalidOffset{ErrorModule::AM, 503};
 constexpr Result ResultInvalidStorageType{ErrorModule::AM, 511};
 constexpr Result ResultFatalSectionCountImbalance{ErrorModule::AM, 512};
+constexpr Result ResultNoData{ErrorModule::AM, 2};
 
 } // namespace Service::AM

src/core/hle/service/am/applet.h

@@ -133,6 +133,9 @@ struct Applet {
     void UpdateSuspensionStateLocked(bool force_message);
     void SetInteractibleLocked(bool interactible);
     void OnProcessTerminatedLocked();
+
+    // Storage channels
+    std::deque<std::vector<u8>> friend_invitation_storage_channel;
 };
 
 } // namespace Service::AM

src/core/hle/service/am/service/application_functions.cpp

@@ -456,8 +456,22 @@ Result IApplicationFunctions::GetFriendInvitationStorageChannelEvent(
 
 Result IApplicationFunctions::TryPopFromFriendInvitationStorageChannel(
     Out<SharedPointer<IStorage>> out_storage) {
-    LOG_INFO(Service_AM, "(STUBBED) called");
+    LOG_DEBUG(Service_AM, "called");
-    R_THROW(AM::ResultNoDataInChannel);
+
+    std::scoped_lock lock{m_applet->lock};
+
+    // Check if there's any data in the friend invitation storage channel
+    if (m_applet->friend_invitation_storage_channel.empty()) {
+        R_THROW(AM::ResultNoData);
+    }
+
+    // Pop the most recent data
+    std::vector<u8> data = std::move(m_applet->friend_invitation_storage_channel.front());
+    m_applet->friend_invitation_storage_channel.pop_front();
+
+    // Create IStorage containing the data
+    *out_storage = std::make_shared<IStorage>(system, std::move(data));
+    R_SUCCEED();
 }
 
 Result IApplicationFunctions::GetNotificationStorageChannelEvent(