add vault (clients/rust/gcli-v2s!22)

* move into function

* remove unnecessary complexity

* wip add phrase generation

* prepare 0.2.7 release

* remove dep

* add predefined keys and update doc

* wip add save from cmd line

* improve error management

* allow to store password-protected secret

* wip use rage for password-encrypted keys

* wip poc for keystore