Address validation for the network module

[b00f]

Description

We currently do not validate the network addresses in the config file. So, if a user enters an incorrect address, the node won't start (an incorrect listen address can even cause a system crash). We need to ensure all addresses, both relay and listen addresses, are valid in the SanityCheck function.

How To Reproduce

1. Open the config file.
2. Change the listen addresses and relay addresses to an incorrect string.

What Happened

The node didn't start. It may also cause a system crash.

Expected Behavior

Should return invalid address error before starting the node.
Write tests for the invalid addressess.

[kehiy]

check: #565

[kehiy]

@b00f we can close it now!