WIP: Add persistent ssh connections

[Dooez]

With :detach and :connect (currently in dev build of neovim) added it makes a lot of sense to have persistent remote connections, with remote-nvim acting as a dashboard for their management.
This is a WIP with basic ssh connection spawning and UI.

Features:

• Explicit sync of workspaces
• Renaming of remote workspaces
• Copying of .config subdirectories
• Reliable global state
• Spawning and killing independent persistent ssh connections

Transfer of .config subdirectories is useful for external tools invoked form neovim e.g. yazi for file preview.

Global state is required for a dashboard, atm i've made rather minimal changes to ensure it's stable.

Currently spawning ssh sessions seems to work ok. I've used sockets for control over persistent ssh sessions and state .json file for additional connection info. Some additional system-wide sync should be added to ensure multiple instances of nvim don't mess with connection while it's being established. -tt flag is required to ensure the remote nvim is closed after the socket is closed.

Any feedback would be appreciated.
I don't use docker or devpod so I cannot really assess if this workflow would work, but it seems possible, though I'm not interested in implementing it.

If you don't see this as a desirable direction for remote-nvim please let me know.