tracker* startup is defined multiple times

[DarkTrick]

This is about
- tracker-miner-fs
- tracker-extract
- tracker-store

Actual Behavior
=================
Their startup is defined in
- ${XDG_CONFIG_HOME}/autostart ( more info: https://wiki.archlinux.org/index.php/XDG_Autostart )
- /usr/lib/systemd/user/tracker*.service

Expected Behavior
===================
Startup is only defined in one place.

Reason:
- Managing the software does not get confusing

lsb_release -rd
================
Description: Ubuntu 20.04.1 LTS
Release: 20.04

ProblemType: Bug
DistroRelease: Ubuntu 20.04
Package: systemd 245.4-4ubuntu3.2
ProcVersionSignature: Ubuntu 5.4.0-48.52-generic 5.4.60
Uname: Linux 5.4.0-48-generic x86_64
ApportVersion: 2.20.11-0ubuntu27.9
Architecture: amd64
CasperMD5CheckResult: skip
CurrentDesktop: XFCE
Date: Wed Sep 23 20:39:33 2020
MachineType: FUJITSU FMVWB3U27
ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-5.4.0-48-generic root=UUID=fe637d00-125b-4a54-adce-3711830d450b ro acpi_osi=! "acpi_osi=Windows 2015" pci=nomsi acpi_osi=Linuxs resume=UUID=8fa6d40f-c23d-497e-9846-f6f26536690d
SourcePackage: systemd
SystemdDelta:
 [EXTENDED] /lib/systemd/system/rc-local.service → /lib/systemd/system/rc-local.service.d/debian.conf
 [EXTENDED] /lib/systemd/system/user@.service → /lib/systemd/system/user@.service.d/timeout.conf

 2 overridden configuration files found.
UpgradeStatus: Upgraded to focal on 2020-07-24 (61 days ago)
dmi.bios.date: 01/23/2018
dmi.bios.vendor: FUJITSU // Insyde Software Corp.
dmi.bios.version: Version 1.07
dmi.board.name: FJNB2BB
dmi.board.vendor: FUJITSU
dmi.board.version: A2
dmi.chassis.type: 10
dmi.chassis.vendor: FUJITSU
dmi.modalias: dmi:bvnFUJITSU//InsydeSoftwareCorp.:bvrVersion1.07:bd01/23/2018:svnFUJITSU:pnFMVWB3U27:pvr:rvnFUJITSU:rnFJNB2BB:rvrA2:cvnFUJITSU:ct10:cvr:
dmi.product.family: LIFEBOOK-JR
dmi.product.name: FMVWB3U27
dmi.sys.vendor: FUJITSU