Allow OS to define config highlighting (pfSense) (#10392)

* Update showconfig.inc.php

Fix display for pfsense config files.

* Update showconfig.inc.php

Change from else if to elseif

* Update showconfig.inc.php

Decode special chars before syntax highlighting.

* Update pfsense.yaml

* Add config_highlighting device property

Add config_highlighting to device definition
Update showconfig.inc.php to use config_highlighting to set language.

* Update showconfig.inc.php

Fix incorrect code. Chose correct variable where config_highlighting is set.

* Update os_schema.json

Add property config_highlighting to schema
 - used for language highlighting when displaying the config file

* Update showconfig.inc.php

includes/definitions/pfsense.yaml

@@ -3,6 +3,7 @@ type: firewall
 group: unix
 text: pfSense
 processor_stacked: true
+config_highlighting: xml
 over:
     - { graph: device_processor, text: 'Processor Usage' }
     - { graph: device_ucd_memory, text: 'Memory Usage' }

includes/html/pages/device/showconfig.inc.php

@@ -316,18 +316,14 @@ if (Auth::user()->hasGlobalAdmin()) {
                           </div>';
     }
     if (!empty($text)) {
-        if (isset($previous_config)) {
-            $language = 'diff';
-        } else {
-            $language = 'ios';
-        }
-        $geshi = new GeSHi($text, $language);
+        $language = isset($previous_config) ? 'diff' : Config::getOsSetting($device['os'], 'config_highlighting', 'ios');
+        $geshi = new GeSHi(htmlspecialchars_decode($text), $language);
         $geshi->enable_line_numbers(GESHI_FANCY_LINE_NUMBERS);
         $geshi->set_overall_style('color: black;');
         // $geshi->set_line_style('color: #999999');
         echo '<div class="config">';
         echo '<input id="linenumbers" class="btn btn-primary" type="submit" value="Hide line numbers"/>';
-        echo htmlspecialchars_decode($geshi->parse_code());
+        echo $geshi->parse_code();
         echo '</div>';
     }
 }//end if