Should preferably only show one status message

[proehlen]

If the connection is broken and overnode was syncing you see both messages. There may be other error / notifications too. Ideally there should only be one status message shown at a time in order of severity:

• Connection lost
• Other important notices
• Overnode is syncing

Since the logic to determine whether the message is shown or not is in each component it might be tricky to pull off but I think it's a nice to have.