Add a duplicate task option to templates to make it consistent with the same process on tasks in projects

Currently on live projects, you have the option to move to (move a task to another project), copy to (copy a task to another project) or duplicate (duplicate a task on the current project.
When editing template tasks, the otions are move to and copy to.  If you wish to duplicate a task, you effectively have to copy it to the current template.

For consistency and ease of use, it would make sense for the options on template tasks to match the options on project tasks and thus have a duplicate option.