[Enhancement] Exception message about consensus logs can be written into error.log

[cloud8little]

Summary or problem description
Exception message about consensus logs can be written into error.log

Do you have any solution you want to propose?
Recently i've run several tests about consensus service, and found that the exception logs are not written to the file error.log, and fortunately I use screen to recover the session so the error logs can be found out. Even though you can use "> xx.log" to log this, this requires you add it when you start the service.

Where in the software does this update applies to?

• CLI

neo-cli: #470
neo: ##1150

Exception like this, currently wallet format error will be logged, but consensus service error won't .

[shargon]

@cloud8little Thanks so much! we will improve a lot of with these tests :)

Now the exceptions are captured by akka

https://github.com/neo-project/neo-cli/blob/8c6de106094a8894c7be2c19768697f9afef774f/neo-cli/Program.cs#L13

So... I think that we need to call this method when akka print the log.

[shargon]

@neo-project/ngd-shanghai do you know if we can merge AppDomain.CurrentDomain.UnhandledException and akka logging in the same method?