Tweaked user feedback icons

[morganist]

In my opinion, user feedback icon (deepin-feedback in Papirus) looks out of place when next to other Papirus icons. It is mainly used in settings lists and at first I thought the icon did not exist and that it was fallbacking to Breeze icon. The issue is, its inner elements are too thin (at all sizes) and they were also very white (#ffffff)

This is how it looks in KDE Plasma:

This is what I propose:

[SmartFinn]

LGFM. You may squash and merge it.

[morganist]

Hooray, looks nicer