MDL-78806 admin: Consistent page title during upgrade and install

* Use the page title separator constant when displaying the page title
during upgrade and installation.
* No need to display the site name during install when because it hasn't
been set at this point.

admin/index.php

@@ -267,7 +267,7 @@
     upgrade_init_javascript();
 
     $PAGE->navbar->add($strdatabasesetup);
-    $PAGE->set_title($strinstallation.' - Moodle '.$CFG->target_release);
+    $PAGE->set_title($strinstallation . moodle_page::TITLE_SEPARATOR . $CFG->target_release, false);
     $PAGE->set_heading($strinstallation);
     $PAGE->set_cacheable(false);
 

lib/installlib.php

@@ -344,7 +344,7 @@ function install_print_header($config, $stagename, $heading, $stagetext, $stagec
           <link rel="shortcut icon" href="theme/clean/pix/favicon.ico" />';
 
     echo '<link rel="stylesheet" type="text/css" href="'.$CFG->wwwroot.'/install/css.php" />
-          <title>'.get_string('installation','install').' - Moodle '.$CFG->target_release.'</title>
+          <title>'.get_string('installation', 'install') . moodle_page::TITLE_SEPARATOR . 'Moodle '.$CFG->target_release.'</title>
           <meta name="robots" content="noindex">
           <meta http-equiv="content-type" content="text/html; charset=UTF-8" />
           <meta http-equiv="pragma" content="no-cache" />

lib/upgradelib.php

@@ -1584,7 +1584,7 @@ function upgrade_started($preinstall=false) {
             $strupgrade  = get_string('upgradingversion', 'admin');
             $PAGE->set_pagelayout('maintenance');
             upgrade_init_javascript();
-            $PAGE->set_title($strupgrade.' - Moodle '.$CFG->target_release);
+            $PAGE->set_title($strupgrade . moodle_page::TITLE_SEPARATOR . 'Moodle ' . $CFG->target_release);
             $PAGE->set_heading($strupgrade);
             $PAGE->navbar->add($strupgrade);
             $PAGE->set_cacheable(false);