feat: Add option for open key write to configurable system

[voiduin]

Script must get open key from three type source

• Local File
• string
• url, for example - open key can stored on git open repo raw link like https://raw.githubusercontent.com/voiduin/linux-host-setup/refs/heads/main/README.md

This feature needed for vscode comfortable work.
If use vscode with username-password auth - user need input password each time when connect or reload window

May be several way for get keys? for example interestig get keys from git username:

variant 1 (better)

--ssh-public-key-string
--ssh-public-key-url
--ssh-public-key-file
--ssh-public-key-github <username>

Or variant 2

--ssh-public-key url:https://example.com/mykey.pub
--ssh-public-key file:/home/user/.ssh/id_ed25519.pub
--ssh-public-key string:ssh-ed25519 AAAAC3NzaC1...
--ssh-public-key github:alice-dev

URLS for some VS
https://stackoverflow.com/questions/16158158/what-is-the-public-url-for-the-github-public-keys

[voiduin]

Flag --ssh-public-key-url implemented in commit
876751a