Initialising services via SymphonyClientConfigBuilder and SymphonyClientConfig

[dayoaws]

Various services follow the pattern below which makes them hard to unit test.
public MessageService(SymphonyClient symClient) {
this.symClient = symClient;
//Lets startup the worker thread to listen for raw datafeed messages
dataFeedWorker = new DataFeedWorker(symClient, this);
new Thread(dataFeedWorker, "DataFeedWorker: "+ symClient.getName()).start();
}

To simplify and reduce the components that need to be initialised in unit testing, i suggest we extract the initialisation of the runnables out of the constructors into a private init method and perform the initialisation based on a new lazyInit attribute added to the ClientConfig and built using the ClientConfigBuilder

[dayoaws]

See the following gist for an example of what the MessageService would look like after the change described above https://gist.github.com/dayoaws/3e3e4898bfc4c9a552558c19ae224efa

this of course assumes that the config was built using the builder and the lazy init flag is a mandatory BuildStep after the withServices buildstep