services: Reorganize services, detect X

Detect X autostart a bit better with a separate service. The service
relies on a shell script which searches for a socket which X creates on
startup and only finishes when it finds the socket succesfully.

This makes services which need X to start successfully a bit more
robust, and while it can still break if X takes too long, it should be
more stable now.

Finally, services can restart more quickly when ended since they don't
require the 2+ `RestartSec` option to be present anymore to successfully
start.

services/.local/share/services/x-started-confirm.sh

@@ -0,0 +1,20 @@
+#!/usr/bin/env bash
+# from: https://superuser.com/questions/759759/writing-a-service-that-depends-on-xorg/1351489#1351489
+
+COUNTER=0
+
+while true; do
+  # Check whether or not socket exists
+  if [ -S /tmp/.X11-unix/X0 ]; then
+    exit 0
+  fi
+
+  ((++COUNTER))
+
+  if [ $COUNTER -gt 20 ]; then
+    printf "X did not start in time\n"
+    exit 1
+  fi
+  printf "X not yet started, counter at %s\n" "$COUNTER"
+  sleep 1
+done