Holiday Bugfixes (#1762)

* Don't show "not much going on" when we are actively downloading

* Swipe to paginate is now behind a flag in the user preferences.

* Added a new server setting for host name, if the server sits behind a reverse proxy. If this is set, email link generation will use it and will not perform any checks on accessibility (thus email will always send)

* Refactored the code that checks if the server is accessible to check if host name is set, and thus return rue if so.

* Added back the system drawing library for markdown parsing.

* Fixed a validation error

* Fixed a bug where folder watching could get re-triggered when it was disabled at a server level.

* Made the manga reader loader absolute positioned for better visibility

* Indentation

API/DTOs/Settings/ServerSettingDTO.cs

@@ -66,4 +66,8 @@ public class ServerSettingDto
     /// If the server should save covers as WebP encoding
     /// </summary>
     public bool ConvertCoverToWebP { get; set; }
+    /// <summary>
+    /// The Host name (ie Reverse proxy domain name) for the server
+    /// </summary>
+    public string HostName { get; set; }
 }