Fix Clipboard clear after time on iOS (#1679)

* Fixed Clipboard clear after x seconds depending on what the user set. Also refactored a bit to make the Clipboard a custom service to provide a better way to handle this situation #1464

* Clear some usings #1464

src/Core/Abstractions/IPlatformUtilsService.cs

@@ -9,7 +9,6 @@ namespace Bit.Core.Abstractions
     {
         string IdentityClientId { get; }
 
-        Task CopyToClipboardAsync(string text, Dictionary<string, object> options = null);
         string GetApplicationVersion();
         DeviceType GetDevice();
         string GetDeviceString();