Cosmos-sdk: Make unit tests to ensure tags get added

[ValarDragon]

ref #2643

We should make sure that tags are actually getting added within unit test cases for each message type.

[jackzampolin]

This is a great task.

[fedekunze]

@jackzampolin can we assign someone else plz ? I have a lot on my plate atm and I agree that we should add these test sooner than later

[alexanderbez]

Either way, this should hold off until the new events system is in place.

[jackzampolin]

Maybe now that the new events system is in place this is a good issue to work on.