Improve icon readability at small size

https://github.com/qbittorrent/qBittorrent/pull/17578#pullrequestreview-1079562121

Co-authored-by: Nowshed H. Imran <nowshed.imran@gmail.com>

src/icons/collapse.svg

@@ -1 +1 @@
-<svg height="32" viewBox="0 0 32 32" width="32" xmlns="http://www.w3.org/2000/svg"><path d="m76 62c0-7.731635-6.268365-14-14-14s-14 6.268365-14 14 6.268365 14 14 14 14-6.268365 14-14zm-8.182596-1.196058-4.989519 5.996443a1.0769231 1.0769231 0 0 1 -1.65577 0l-4.989519-5.996443a1.0769231 1.0769231 0 0 1 .827212-1.76548h9.980384a1.0769231 1.0769231 0 0 1 .827212 1.76548z" fill="#1e90ff" stroke-width=".067308" transform="translate(-46 -46)"/></svg>
+<svg height="32" viewBox="0 0 32 32" width="32" xmlns="http://www.w3.org/2000/svg"><path d="m62 48c-7.731619 0-14 6.268381-14 14s6.268381 14 14 14 14-6.268381 14-14-6.268381-14-14-14zm-6.826172 10.21875h13.652344c1.001007 0 1.540059 1.251253.888672 2.0625l-6.824219 8.5a1.1719094 1.2504823 0 0 1 -1.779297 0l-6.826172-8.5c-.653336-.811247-.112332-2.0625.888672-2.0625z" fill="#1e90ff" transform="translate(-46 -46)"/></svg>