Enhance tests and their coverage

[masesdevelopers]

Is your feature request related to a problem? Please describe. Current tests cover a portion of the possible usages of JNet

Describe the solution you'd like Add more tests to cover more functionalities, e.g.

• add listeners
• add performance measurement

Describe alternatives you've considered N/A

Additional context N/A

[masesdevelopers]

Try to add tests for JNetCLI and JNetPS

[masesdevelopers]

Add tests for listeners as requested from #679