Small tweak to HA's developer tool UI

As a new HA user, I’m still getting used to how the developer tools work. Most-often, I load services when I really wanted states. Or something like that. I think a good fix would be to add html title tags to the buttons. So where we’ve got

<paper-icon-button alt="States" ... >
it should be updated to
<paper-icon-button alt="States" title="States" ... >

In most browsers, title gives you a tooltip on hover.