Fix incorrect margins in 16/22px media icons
For some reason, the margins on these icons were 1 px larger on each side than they were supposed to be.
Also delete media-mout and make media-record look like it does at other icon sizes. I think media-mout is a spelling error and someone forgot to fix it instead of also adding media-mount.
Reviewers: VDG, ngraham
Reviewed By: VDG, ngraham
Differential Revision: https://phabricator.kde.org/D24628