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>

OpenText/source/HostExplorer/Keymap/Default.kmv

@@ -0,0 +1,9 @@
+[KEYMAP]
+Normal Entries=1
+Normal0=Backspace,Delete
+Shift Entries=0
+Ctrl Entries=0
+ShiftCtrl Entries=0
+Alt Entries=0
+ShiftAlt Entries=0
+AltCtrl Entries=0