ReplayGain and little bugfix
- Updated app icon (yeah, again)
- Finally introduced ReplayGain https://codeberg.org/M23Snezhok/Vinyl/pulls/53
- Added adaptive window title https://codeberg.org/M23Snezhok/Vinyl/pulls/50
- Fixed accent color for volume icon https://codeberg.org/M23Snezhok/Vinyl/pulls/52
- Made icons are theme-independent https://codeberg.org/M23Snezhok/Vinyl/issues/44