Removed unused code: ping and stale messages
Detached UnicastSync send and sync part so that we would be able
to await for message in the code.
Added sys::Async to be able to handle situations where we want to
sync to the response, but after some time.
Fixed messages logging: for some reason demangling abi use caused
bad system behaviour
Forced each message to have declared type as parts of Bus logic
depends on it and previously we encountered undefined
behaviours. Added tests and messages validators.
