As a developer, I want to fix runtime errors in p2p so that the node is nicer with peers

[vlad9486]

There are three kind of errors happens all the time:

• Connection not found
• Invalid yamux state
• Invalid noise state

[vlad9486]

Fixed mio service to deregister connection on epoll as disconnect.

Added P2pPeerStatus::Disconnecting case to track connection where disconnect is in progress.

Try to postpone removing connection state in network state machine until connection is disconnected on mio service.

[vlad9486]

Fixed bugs related to disconnection. Pass all tests.