Add OpenText/brother installers and update printer installer scripts

- New PrinterInstaller support for Brother MFC-J series (driver source,
  DSI files; binaries gitignored)
- New OpenText HostExplorer 15 installer (profiles, shortcuts, .iss;
  .exe/.cab/.msi gitignored)
- New HP printer driver support files (.gpd/.cfg/.xml/.dtd) for 3556
  model series
- PrinterInstaller.iss rework with additional driver paths
- FQDNUpdate, MachineAuth, XeroxOfflineInstaller minor updates

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

HPOfflineInstaller/drivers/hp_x32/hpcu3556.hpx

@@ -0,0 +1,13 @@
+[RegEntries]
+MystStdInstall=1
+DemFileName=hpcu355.dem
+VerifyPDL=PCL6
+ExtensionDlls=hpmux355.dll
+RealCfgDll=UNIDRVUI.DLL
+EnableIE7Launch=0
+UIExtensionDll=hpcui355.dll
+
+[RegType]
+;dword=1, string=0
+EnableIE7Launch=1
+MystStdInstall=1