Add national days API to calendar

Calendar/Service/Models/NationalDays/Meta.cs

@@ -0,0 +1,17 @@
+using JetBrains.Annotations;
+using System.Text.Json.Serialization;
+
+namespace ChrisKaczor.HomeMonitor.Calendar.Service.Models.NationalDays;
+
+[PublicAPI]
+public class Meta
+{
+    [JsonPropertyName("cache_status")]
+    public string CacheStatus { get; set; } = string.Empty;
+
+    [JsonPropertyName("response_count")]
+    public int ResponseCount { get; set; }
+
+    [JsonPropertyName("request_type")]
+    public string RequestType { get; set; } = string.Empty;
+}