Streamline TestNG listener instantiation

[krmahadevan]

TestNG Version

Note: only the latest version is supported
7.6.1

Currently TestNG instantiates listener objects multiple times and throws away duplicate instances if the listener has been wired in.
This becomes a problem for people who also use their listener objects to manage state.

This issue is to track this discrepancy in TestNG and ensure that listeners are instantiated ONLY if they are going to be wired in.

Please see this discussion for more context.