Sound Settings Update + HUD Icons — Idle Together Steam update #1470299

This update follows the improvement of the game's sound design. To take full advantage of the new sounds, I had to update the settings system to allow more precise volume control (1 by 1 instead of 5 by 5), and also tweak the way the sound feels so it comes across as more linear to the ear. As a result, the sounds may seem quieter than before, you’ll likely need to turn them up significantly. In addition, the visuals of the sound bars have been redesigned to better match the pixel art style. Finally, the in-game HUD visuals have been updated, all icons are now more stylized. Big thanks again to Stalosir for his work ! By the end of the month (hopefully), more visuals will be added, including the long-awaited cursors!