Add mainnet node sync check

[darcius]

Add in a check to make sure the CLI only operates if the mainnet node is fully synced. Give a nice error message if commands that need the mainchain to operate are tried.

[moles1]

Have made it so that all commands which need the pow chain will sync automatically before doing anything - sync progress is rendered (if syncing is necessary), and once done it will move onto the remaining logic.

For daemons, any logic which requires the pow chain will sync before a method is called or a transaction is sent. Syncing progress isn't rendered so that the logs aren't filled up with junk.