Audio Normalized + other changes

"Deselect_character.mp3" sound has been removed. Use the
"button_click.mp3" sound for deselection now.

"Character2_selected.mp3" sound should be delayed and play AFTER the
second "button_click.mp3" sound (when the second character is selected)

Took out all the character sounds (happy, hungry, sad)

New Audio
"taste_neutral.mp3", "taste_matched.mp3" and "taste_double_matched.mp3"
has been included in the new commit and beta asset list. These will be
a replacement of the character sounds to emphasis when a taste is
satisfied, normal or both tastes are satisfied.