Prefix functionality - Allow this also for new tasks after template copy

Currently during the copy of a template it is possible to define a prefix that is added to all tasks that are part of that template. This allows to easy distinguish of tasks of projects based on the same template.

After the template is copied and you add new tasks the project based in that template it would be useful that these new tasks also have this prefix. This will allow for all tasks  of that project to easy distinguish them from other tasks from other projects

This gives also some additional useful functionality like:

Sorting of tasks will be more consistent as now all tasks with prefix are grouped together and new tasks will be before or after them.

Prefix could be used as a "project code" to clearly distinguish all task for a specific project