Add Option for Local Headless Mode in SettingsOverlay

[Akamig]

Uh, I think @FioX0 mentioned this before which I forgot, that after headless-less launcher, we slashed connection between Launcher and headless, but It is true that there's still demand for manage local headless, like snapshots, I guess?

So while it's not possible to re-add snapshot managing code in launcher (since they run completely seperated), we can re-add radio box to use local headless when checked. ignoring RemoteNodeList and forcing localhost.

I think it's easier than handling config.json directly.