console.lua: only clip items between UTF-8 characters

Since with the new horizontal scrolling the end of lines can be visible,
ensure not to clip lines in the middle of UTF-8 characters to not show
mojibake, also adding … to show when items are clipped.

Also replace the existing use of ⋯  with …

player/lua/console.lua

@@ -1693,7 +1693,9 @@ mp.register_script_message("get-input", function (script_name, args)
         end
 
         for i, item in ipairs(args.items) do
-            selectable_items[i] = item:gsub("[\r\n].*", "⋯"):sub(1, limit)
+            local last = next_utf8(item, limit) - 1
+            selectable_items[i] = item:gsub("[\r\n].*", "…"):sub(1, last) ..
+                                  (last < #item and "…" or "")
         end
 
         calculate_max_item_width()