Add xinput short list

In this commit module `xutil` is added which will contain utility
functions relatd to xorg (e.g. xinput, xrandr and ...).

modules and classes inside xutil are wrappers around those binaries.

src/scripts/python/xutil/common.py

@@ -0,0 +1,10 @@
+import subprocess
+
+ENCODING = 'utf-8'
+
+def get_list_short():
+    """Returns string output of the `xinput --list --short` command encoded as
+    UTF-8"""
+    completed = subprocess.run(
+        ['xinput', '--list', '--short'], capture_output=True)
+    return completed.stdout.decode(ENCODING)