Allow changing listening ip addresses (#1713)

* Allow changing listening ip address

* Use Json serialize for appsettings.config saving

* BOM

* IP Address validation

* ip address reset

* ValidIpAddress regex

API/Entities/Enums/ServerSettingKey.cs

@@ -110,5 +110,9 @@ public enum ServerSettingKey
     /// </summary>
     [Description("HostName")]
     HostName = 20,
-
+    /// <summary>
+    /// Ip addresses the server listens on. Not managed in DB. Managed in appsettings.json and synced to DB.
+    /// </summary>
+    [Description("IpAddresses")]
+    IpAddresses = 21,
 }