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

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

* Added @Zeno- const

builtin/common/misc_helpers.lua

@@ -723,3 +723,28 @@ function core.pointed_thing_to_face_pos(placer, pointed_thing)
 	end
 	return fine_pos
 end
+
+function core.string_to_privs(str, delim)
+	assert(type(str) == "string")
+	delim = delim or ','
+	local privs = {}
+	for _, priv in pairs(string.split(str, delim)) do
+		privs[priv:trim()] = true
+	end
+	return privs
+end
+
+function core.privs_to_string(privs, delim)
+	assert(type(privs) == "table")
+	delim = delim or ','
+	local list = {}
+	for priv, bool in pairs(privs) do
+		if bool then
+			list[#list + 1] = priv
+		end
+	end
+	return table.concat(list, delim)
+end
+
+assert(core.string_to_privs("a,b").b == true)
+assert(core.privs_to_string({a=true,b=true}) == "a,b")