scaffolding: take --path intro consideration

[ilgooz]

Some starport s commands has a --path option and some do not. Let's add it to all of them.

Also, in the templates package, we use os.Stat -and also r.Disk.Find?- with vanilla file paths but we need to take --path into consideration as well.

[ilgooz]

Also auto discover root dir see: #1497

[fadeev]

How does auto-discover works with --path? I think we can do the following:

1. If --path, use that as root
2. Else, if current dir is root scaffold in the current dir
3. Else, auto-discover root and scaffold there

[ilgooz]

That's the idea. 👍