FEAT #13671 TIME 4:00 Prerequisites installer + several fixes

rest/index.php

src/app/attachment/controllers/AttachmentController.php

src/app/contentManagement/controllers/JnlpController.php

src/app/convert/controllers/ConvertPdfController.php

src/app/resource/controllers/ResController.php

src/app/resource/controllers/WatermarkController.php

src/core/controllers/InstallerController.php