Create 'dynamic config' that can be changed at 'runtime'

[mm-near]

we already have config.json - which is read at startup.

We should also create another config (dynamic.json?) that would be read after each change, without having to restart the node.

Of course only a few things could be added there.

[mm-near]

One thing that would be good to have - is a way to change the 'current approval' height - this would have sped up the network recovery.

[mm-near]

Another thing might be a blacklist for selected nodes / validators / chunk producers.