add mutex debug script to monitor mutex usage

This provides more information about why the system isn't suspending
than the icons in the status bar do, and can hopefully replace them
since they seem to cause a lot of confusion.

Signed-off-by: Willow Barraco <contact@willowbarraco.fr>

scripts/core/sxmo_mutex_debug.sh

@@ -0,0 +1,11 @@
+#! /bin/sh
+# SPDX-License-Identifier: AGPL-3.0-only
+# Copyright 2022 Sxmo Contributors
+
+# include common definitions
+# shellcheck source=scripts/core/sxmo_common.sh
+. sxmo_common.sh
+
+sxmo_mutex.sh can_suspend list
+
+tail -f "$XDG_STATE_HOME"/sxmo.log | stdbuf -oL grep 'sxmo_mutex.sh'