Add campaign manager

Hcs.WebApp/BackgroundServices/CampaignManagementState.cs

@@ -0,0 +1,27 @@
+using Hcs.WebApp.Data.Hcs;
+using System.Collections.Concurrent;
+
+namespace Hcs.WebApp.BackgroundServices
+{
+    public class CampaignManagementState
+    {
+        private readonly ConcurrentQueue<Campaign> campaigns = new();
+
+        public event Action<Campaign> OnCampaignStarted;
+
+        public void EnqueueCampaign(Campaign campaign)
+        {
+            campaigns.Enqueue(campaign);
+        }
+
+        public bool TryDequeueCampaign(out Campaign campaign)
+        {
+            return campaigns.TryDequeue(out campaign);
+        }
+
+        public void InvokeOnCampaignStarted(Campaign campaign)
+        {
+            OnCampaignStarted?.Invoke(campaign);
+        }
+    }
+}