improve rendering of turn-restriction boxes in narrow sidebars
improve rendering of turn-restriction boxes in narrow sidebars

Previously the applied paddings were too large for narrow sidebars, causing the turn-restriction min-map view to be much more zoomed out than needed.
This tweaks the paddings such that even for the slimmest sidebar the rendering is still acceptable (i.e. no turn arrows to be rendered completely outside of the viewport) and at the same time allows generous margins for wider sidebars.

This also fixes a minor bug where the mini-map is not properly alligned vertically

openstreetmap/iD,openstreetmap/iD,openstreetmap/iD