A single skeleton row should appear while loading, but selection should be on second-to-last row

[tjayrush]

I like that we've removed the skeleton rows. I think that's the right move. It behaves much more intuitively now, however, I think I still want exactly one skeleton row to show up no matter how many more rows we're loading. When I hit the end key, after re-loading a new address with a lot of transactions, the selection should go to the last loaded row, but there should be a single skeleton row showing as an indicator that we're still loading (notwithstanding the fact that the user can see this by looking at the progress bar.)