Explorer should show the storage used in a particular action

[doriancrutcher]

A user in office hours brought up a great point about the explorer.

It would be very useful to see how much state a particular action has taken up on an account.

In this use case he was trying to see how big a deployed wasm file was, and we were curious if this would appear in the deploy action on the explorer.

It was actually surprising to see that we couldn't as I think this could be useful for understanding how much cost in storage staking contract account is paying and what's taking up most of these costs.

So anyway I think this could be a useful feature.