Improve Router class's arguments validation

[pedromassango]

I've just improved the Router class by:

• Assert that routeName is not null
• Asserting that transaction argument must not be null
• Asserting that only module or child must be provided and never both
• Fix routeName null if the function copyWith is called without providing the routeName property

[jacobaraujo7]

Hello.
Thanks for your pull!
Have errors in unity test, please, check logs

[pedromassango]

Hello.
Thanks for your pull!
Have errors in unity test, please, check logs

Ok, it was failing because some tests was not meeting the requirement