Simple way to create shared folder between multiple users in QtPass

[MurzNN]

At now it's too hard to create shared with other users pass folder via QtPass UI: there are no ways to export current user public gpg id, import other users public gpg ids to folder, re-encrypt passwords after adding new user, etc.

Please make "Share" menuitem on folders, that provide dialog for export your public gpg id, import other users public gpg ids, bulk re-encrypt passwords, and short text hints why we need to do this.