Fix notification drawer right safe area inset (#54230)

Apply the right safe-area inset to the full-width notification drawer

The drawer spans the full viewport whenever narrow is true (viewport
under 870px), but the right inset padding on the header and list was
only applied below a 450px media query. Between those widths the close
button ended up under the right inset. Reflect narrow as an attribute
and key the padding off it so the inset follows the same rule as the
drawer width.