Show node name in the main screen

[prusnak]

Describe the feature

I am using multiple backend nodes with my ZeusLN and sometimes it is hard to tell which one I am connected to. I know there are icons, but these can be hard to read by some people.

Suggestion: add the selected node name to main screen.

Btw, Slack does the same for workspaces (i.e. it does not show only the icon, but also the workspace name):