Customize Menus: Menu list arrows aren't vertically centered

[melchoyce]

See attached screenshot of how it is now, and an image how it should be.

[dualcube_subrata]

Menu list arrows are vertically centered new

[celloexpressions]

Note that this is not specific to menus. All customize section arrows are currently top-aligned, not centered, since this design was introduced in 4.3.

Does top or center-aligning work better visually when a majority of section titles are only a single line and only a few are taller? We should document screenshots of those situations with this change.

[afercia]

Also, what if the translation or the menu name are so long that there are actually 3 lines of text?

[melchoyce]

Between top.png​ and centered.png​, I definitely prefer the center alignment for the arrow.

[Dualcube]

In terms of look and feel I am with @melchoyce, as otherwise it looks odd when we have both single line and multiple lines menu items.

[melchoyce]

In 41808:

Customizer: Vertically center section arrows.

Props dualcube_subrata.
Fixes #42123.