project manager template overhaul

[johrstrom]

This is likely an epic in it's own right, but I'll leave that for a bit later, I just wanted to make a ticket now and put some thoughts down.

Right now in the project manager, there's no clear easy way to make a template. That's what this ticket is meant to improve - streamlining the creation of project templates.

Obviously we can look at how the job composer (myjobs) does this now, but I know for sure that templates are a bit of a first class citizen in how they're handled (especially WRT to how they're created).

• project manager templates - manifest support for files to copy #3987
• button for creating templates #3999
• import template from tar.gz/zip #4000
• support for editing template manifest properties. #4001