Additional row of map area could be gained by merging top area

[jidanni]

Description

Just the other day I realized that one entire row of precious screen real estate could be salvaged and reappropriated to the main map area!

All that needs to be done is compact the two lines via the red arrows, into one line!

Screenshots

(Naturally I have snipped off a few complications on the left and right ends to enhance my point. But you get the picture!)

[danieldegroot2]

Or, by removing the header entirely as in the development mirror https://ideditor.netlify.app/ .
However, the iD editor is contained within the osm.org website.
The header is preferably reserved for osm.org UI only, to stay consistent with the rest of the website.
Also, this keeps maintenance needed for the combination to work low.

The v3 prototype moved towards / discussed this but noteably also new tools were added ( #7368, #6717 )
As for narrower screens, see also #7639.