Relocate MunkiStatus.app and Munki-notifier.app to ../Contents/Helpers/ from ../Contents/Resources/ - Munki6dev base (#1207)

* Relocate MunkiStatus.app and Munki-notifier.app to ../Contents/Helpers/ from ../Contents/Resources/

- Updated location of munki-notifier in code/apps/Managed Software Center/Managed Software Center/Controllers/MainWindowController.swift
- Added code/client/installhelper script
- Amended code/tools/make_munki_mpkg.sh with new locations for munki-notifier and MunkiStatus as well as changes required to leverage `installhelper`
- Amended code/tools/pkgresources/Scripts_app_usage/postinstall to leverage `installhelper`
- Deleted code/tools/pkgresources/Scripts_app_usage/preinstall as the actions within should be handled now by `installhelper`
- Amended code/tools/pkgresources/Scripts_launchd/postinstall to leverage `installhelper`
- Amended launchd/LaunchAgents/com.googlecode.munki.munki-notifier.plist to use the new path to munki-notifier.app
- Amended launchd/LaunchAgents/com.googlecode.munki.MunkiStatus.plist to use the new path to MunkiStatus.app

This is a resubmission of https://github.com/munki/munki/pull/1203, which needed it's base branch changing from `main` to `Munki6dev`

* Update installhelper

 - Removed CHECK_TIME global - 374fbaf922 (r1515000516)
- Remove erroneous login window comments - 374fbaf922 (r1515006835) and 374fbaf922 (r1515006962)
- Simplified IF condition - 374fbaf922 (r1515005565) this was in place incase LimitLoadToSessionType contained multiple values (as it can).

* Update installhelper

- Reverted changes made for - 374fbaf922 (r1515005565)
- Changed constant/global PASSED_ARG to local: launchd_group - https://github.com/munki/munki/pull/1207#discussion_r1515002646 and https://github.com/munki/munki/pull/1207#discussion_r1515002968

* Update installhelper

* Update installhelper

* Update installhelper

* Update installhelper

* Update make_munki_mpkg.sh

Amended so that the launchd pkg is installed by default

code/tools/pkgresources/Scripts_app_usage/postinstall

@@ -1,22 +1,19 @@
 #!/bin/sh
 
-# Lovingly adapted from Per Olofsson
-# https://github.com/MagerValp/Scripted-Mac-Package-Creation/blob/master/scripts/postinstall
+#
+# this postinstall should run installhelper in the background, with it then waiting until
+# managedsoftwareupdate isn't running and then (re)load Munki's appusage launchditems items as needed
+#
 
-export PATH=/usr/bin:/bin:/usr/sbin:/sbin
-
-# Execute postinstall actions if we're installing on a live system.
-# This is useful for loading launch daemons and agents.
-if [ "$3" = "/" ]; then
-
-    # Run postinstall actions for root.
-    launchctl bootstrap system/ /Library/LaunchDaemons/com.googlecode.munki.appusaged.plist
-
-    # Run postinstall actions for all logged in users.
-    for uid in $(ps -axo uid,args | grep "/[F]inder.app/" | awk '{print $1}'); do
-        launchctl bootstrap gui/"$uid"/ /Library/LaunchAgents/com.googlecode.munki.app_usage_monitor.plist
-    done
-
-fi
-
-exit 0
+# Only execute postinstall actions if we're installing on a live system.
+if [ "$3" = "/" ]
+then
+    installHelper='/usr/local/munki/installhelper'
+    if [ -f  "${installHelper}" ]
+    then
+        /bin/echo "Loading ${installHelper}..."
+        "${installHelper}" appusage &
+    else
+        /bin/echo "Cannot locate: ${installHelper}..."
+    fi
+fi