Watcher-Info data update might cause issue under a load

[pnowosie]

Concern raised by @pgebal in the review of #1496.

Watcher-Info consumes events from Watcher via OMG.Bus. There are several consumers to handle specific events, but they are uncoordinated. It might be that Watcher-Info's BlockApplicationConsumer is very late in applying new blocks, but other consumers, e.g. regarding IFE are spending not yet created outputs. Which means that when handler will finally catch up on blocks it creates UTXOs that should have been spend by exits.

Potential solution would be to coordinate syncing like the Watcher do and not progress with some of consumers if others are straggling.