Make results delegate list items a bit taller with bigger icons

We generally use the smallMedium (22px) icon size for small-ish-but-not-too-small icons as they have a better visual balance with adjacent text, compared to the small (16px) icon size. 22px icons also generally look better than 16px icons. Moving the results list items to use smallMedium icons offers a better visual balance, and adding a tiny of vertical padding balances out everything a bit more to provide more "breathing room" between the rows.

As a consequence, the maximum number of results visible at once has to decrease a bit, but this is generally not a major problem as the user can simply keep typing to refine their search to find what it is they're looking for.

BUG: 422567 FIXED-IN: 5.23

Before, small number of results	After, small number of results

Before, medium number of results	After, medium number of results

Before, large number of results	After, large number of results

cc @teams/vdg @alex