Ensure live status requests are always batched (#4713)

mocks/include/mocks/EmptyApplication.hpp

@@ -76,6 +76,11 @@ public:
     {
         return nullptr;
     }
+
+    ITwitchLiveController *getTwitchLiveController() override
+    {
+        return nullptr;
+    }
 };
 
 }  // namespace chatterino::mock

mocks/include/mocks/Helix.hpp

@@ -86,6 +86,12 @@ public:
                  std::function<void()> finallyCallback),
                 (override));
 
+    MOCK_METHOD(void, fetchChannels,
+                (QStringList userIDs,
+                 ResultCallback<std::vector<HelixChannel>> successCallback,
+                 HelixFailureCallback failureCallback),
+                (override));
+
     MOCK_METHOD(void, getChannel,
                 (QString broadcasterId,
                  ResultCallback<HelixChannel> successCallback,