Allow fscopy/fsmove to act recursively

[nrdxp]

Summary

I see in https://github.com/gopasspw/gopass/issues/1831#issuecomment-796603844 that the fs* commands are in need of a better story. I think these commands could be quite useful for recreating a directory structure of secrets if you allow them to act recursively, that is decrypt an entire folder of secrets to their respective paths on the filesystem and vice versa.

To try and illustrate a bit more clearly, if I had the dir structure:

  .
  ├── baz
  │  └── bar
  │     └── sec1
  └── foo
     ├── bar
     │  └── sec2
     └── baz
        └── sec3

Then I could use these commands to import/export this entire structure in/out of gopass. Could be quite useful for quickly putting secrets in place on a remote server, for example.

[dominikschulz]

Yes, indeed. This sounds like a very good use case.

Maybe you could try to come up with a succinct PR creating this kind of documentation in the docs folder?

Once we have agreed upon that I can probably take care of the implementation part.

[devhell]

Recursively adding files to the store would be great. Particularly, bulk-managing SSH keys would be easier.