Add Templates to Projects in Bulk

[#1]

By selecting multiple projects and clicking "Edit", we should have the option to add a project template to all the projects selected.

Use case: we have many projects that all need one task added to them. Instead of adding the task to each project one by one, we want to create a template with the one task and attach this template to all projects in buik.

[#2]

This is a simple but very useful functionality that should exist. It is a great way to make mass updates of core project configuration in many projects, that is not able to be handled in any way except by brute force (one by one).