Add "protection_bypass" priv.

The access privilege allows players that have it to bypass protection
on locked doors/trapdoors, chests and bones.

The priv also allows bypassing any minetest.is_protected() check,
including digging nodes and placing them. It is meant for world
moderators to clean up and fix map issues.

Original patch by red-001. Split up and rebased/rewritten by sofar.

This patch requires https://github.com/minetest/minetest/pull/3800

mods/default/nodes.lua

@@ -1414,6 +1414,9 @@ end
 local function has_locked_chest_privilege(meta, player)
 	local name = ""
 	if player then
+		if minetest.check_player_privs(player, "protection_bypass") then
+			return true
+		end
 		name = player:get_player_name()
 	end
 	if name ~= meta:get_string("owner") then