Right now, `SwipeListItem` isn't as convergent as it could be. It always uses a very
large margin between actions, and its right margin doesn't take into account the
visibility of the scrollbar, so it's always too much.
This patch makes the spacing conditional on form factor, and takes into account the
Note: the scrollbar part of the patch doesn't actually work and always goes down the
codepath for not having a scrollbar visible. It's copied from implementation of the
drag handle, where it also doesn't work.I couldn't figure out how to fix it. Help
would be appreciated, or else we could land this and then fix them both in a