Add options for OSD feedback

Summary:
Extend configuration knobs for visual feedback by adding separate ones
for output volume, input volume and mute state.

BUG: 363983
FIXED-IN: 5.19.0

Reviewers: VDG, Plasma, broulik, ngraham, drosca, cblack

Reviewed By: VDG, Plasma, ngraham, cblack

Subscribers: The-Feren-OS-Dev, cblack, drosca, ngraham, plasma-devel

Tags: Plasma

Differential Revision: https://phabricator.kde.org/D28281