Move default entity tabs to secondary tabs

[Symbioquine]

@mstenta

this would affect mobile real-estate in that regard, because it would add sub-tabs where there aren’t any currently. And those can’t be collapsed.

That seems concerning. Albeit, it would be a bit of a weird UX to have two expanding/collapsing menus at the top also. Surely, there’s a more compact way for both to fit into the page on mobile…