[rust] config tool does not create .libra/genesis directory

[n-uke]

Describe the bug
Both "libra config validator-init" and "libra config fullnode-init" assume that there is an already-existent .libra/genesis folder to set up the configurations for a validator or fullnode. The folder .libra is also not created by these commands.

To Reproduce
Steps to reproduce the behavior:

1. Install and build libra on a clean server
2. Run commands "libra config validator-init" or "libra config fullnode-init"
3. The terminal will output an error message describing that the directory could not be found. ("Failed to execute config tool, message: No such file or directory (os error 2)")

Expected behavior
The tool should create the directory if it doesn't already exists.

Desktop (please complete the following information):

• OS: Ubuntu 22.04.4 LTS

Additional context
The error is thrown in "download_genesis".

[sirouk]

Thanks Nuke!

This was my doing.