[Exe Thumbnailer] Improve icon selection algorithm

Authored by broulik on Aug 22 2018, 10:28 AM.

Description

[Exe Thumbnailer] Improve icon selection algorithm

Prefer downsampling over upscaling, and also prefer higher BPP

CHANGELOG: Thumbnailer for EXE and ICO files now prefers higher quality icons, if available

Differential Revision: https://phabricator.kde.org/D14308