Sort connector names for multi-screen size/position keys
A string including the connector names is used in the config file key for storing per-screen-arrangement size and position data, which means we need this string to be consistent for the same screen arrangement. But connector order is non-deterministic. We need to sort the list to keep a consistent order and avoid losing multi-screen size and position data.
(cherry picked from commit 3f84ef82)
Edited by Nate Graham