add alert/notification functionality (for server connection events and messages)

SharedLibraryCore/Alerts/Alert.cs

@@ -0,0 +1,33 @@
+using System;
+using Data.Models.Client;
+
+namespace SharedLibraryCore.Alerts;
+
+public class Alert
+{
+    public enum AlertCategory
+    {
+        Information,
+        Warning,
+        Error,
+        Message,
+    }
+
+    public class AlertState
+    {
+        public Guid AlertId { get; } = Guid.NewGuid();
+        public AlertCategory Category { get; set; }
+        public DateTime OccuredAt { get; set; } = DateTime.UtcNow;
+        public DateTime? ExpiresAt { get; set; }
+        public string Message { get; set; }
+        public string Source { get; set; } 
+        public int? RecipientId { get; set; }
+        public int? SourceId { get; set; }
+        public int? ReferenceId { get; set; }
+        public bool? Delivered { get; set; }
+        public bool? Consumed { get; set; }
+        public EFClient.Permission? MinimumPermission { get; set; }
+        public string Type { get; set; }
+        public static AlertState Build() => new();
+    }
+}