add paintings value

paintings can have value,
when the player steals the painting, the value gets added to a list of
stolen paintings of the player,
when reaching the escape zone, the values get added up,
for now the „totalEarnings“ variable is not used furthermore.
Also: only player can steal paintings now, when a cop presses a
painting corner, nothing happens.

unrelated observed bug:
sometimes a duel gets triggered (when the player starts a game alone?)