Network Adapter Refactoring and Tests

There were a few confusing naming conventions specifically with network adapter and network service that i clarified.

There was also some circular logic in the network adapter code that needed more clarification. 
The NetAdapter interface now contains the HandleMessage method. 

Network Adapter needed tests so I went ahead and implemented some tests. 2 of the tests will fail because they depend on a TODO method from Brian, so they are currently commented out. 
Is there not a function for this elsewhere already?