doSharpBlocks gamerule

So currently cacti and sweet berries can cause damage when you touch them. This gamerule would allow a player to toggle off this feature. When true, sharp blocks (currently cacti and sweet berries, but could include damage from falling onto dripstone and amethyst crystals (dripstone that lands on a player would do damage like any falling block), possibly coral (without boots because coral is sharp) could damage a player (or poke them to death) when false, however, a player would not be damaged by these blocks.