[CSM] Add function to get player privileges (#5933)

* [CSM] Add function to get player privileges + move related help functions to common

* Added @Zeno- const

clientmods/preview/init.lua

@@ -150,3 +150,9 @@ core.register_on_punchnode(function(pos, node)
 	return false
 end)
 
+core.register_chatcommand("privs", {
+	func = function(param)
+		return true, core.privs_to_string(minetest.get_privilege_list())
+	end,
+})
+