Upgrade and move information about database-chain synchronization to navbar
We want to display some icon to inform user about synchronization of database and blockchain.
- Green icon if the blocks in database are the same or less than 3 block from headblock in chain.
- Yellow in between 3 and 20 blocks difference.
- Red for more than 20.
And keep it in navbar, not in home page, because it may be useful in Account page or witnesses list.