Thanks @wctaylor.
Even there is no other file in " ~/.local/share/applications/" (I thought the other applications should have a .desktop file there as well) your solution is correct.
My Tor_Browser.desktop file looks like this now (copied the content from a “start-tor-brower.desktop” file which appeared in the extracted browser path after starting Tor ones using the bash script file: “<path_to_extracted_tor>/Browser/start-tor-brower”):
[Desktop Entry]
Type=Application
Name=Tor Browser
GenericName=Web Browser
Comment=Tor Browser is +1 for privacy and -1 for mass surveillance
Categories=Network;WebBrowser;Security;
Exec=sh -c ‘“<path_to_extracted_tor>/Browser/start-tor-browser” --detach || ([ ! -x “<path_to_extracted_tor>/Browser/start-tor-browser” ] && “$(dirname “$*”)”/Browser/start-tor-browser --detach)’ dummy %k
X-TorBrowser-ExecShell=./Browser/start-tor-browser --detach
Icon=<path_to_extracted_tor>/Browser/browser/icons/mozicon128.png
StartupWMClass=Tor Browser
A reboot was necessary in my case otherwise I could not open the menu to click on “Add to Favorites”.