Make icons label-sized

Anywhere we have an icon and a label next to each other, it looks nice when they both have roughly the same heights. When they don't, the icon can feel too large, a bit visually overpowering.

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Part of teams/vdg/issues#29. See that issue for explanation and screenshots.

Plasma companion to frameworks/breeze-icons!371 (closed).

If you have conceptual issues with this or think it looks ugly, please comment in teams/vdg/issues#29. Implementation comments only, please.