DTOs for index mostly done, doing DB models

SVSim.EmulatedEntrypoint/Models/Dtos/DateRange.cs

@@ -0,0 +1,12 @@
+using MessagePack;
+
+namespace SVSim.EmulatedEntrypoint.Models.Dtos;
+
+[MessagePackObject]
+public class DateRange
+{
+    [Key("begin_time")]
+    public DateTime BeginTime { get; set; }
+    [Key("end_time")]
+    public DateTime EndTime { get; set; }
+}