Ensure action tags are added for all msg types

[cwgoes]

This allows users to search for particular types of transactions. Action tags don't yet exist in x/bank, and may also need to be added elsewhere.

cc @gamarin2

[gamarin2]

We need this for launch, at least for bank module @cwgoes

[mossid]

To avoid adding action tags manually, we can add result.Tags = append(result.Tags, sdk.NewTag("action", reflect.TypeOf(msg).Name())) in runTx

[rigelrozanski]

Meh not too big of a fan of defining Tags in multiple locations, I'd personally like to see them consolidated, but doesn't super matter

[ValarDragon]

result.Tags = append(result.Tags, sdk.NewTag("action", reflect.TypeOf(msg).Name()))

alternatively, I think adding a name function to msgs is reasonable. The purpose would be just to avoid reflection here. With reflection, any name change for the message struct is a state breaking change.

I like the idea of avoiding adding action tags manually.

[alexanderbez]

++ @ValarDragon & @rigelrozanski