MDL-74141 tool_task: Display error when Path to CLI not defined

When "Path to PHP CLI" is not defined, an exception with the message
in cannotfindthepathtothecli should be displayed, and the page should
be redirected to System paths settings page.

Apart from that, this patch also replaced core_task to tool_task,
because this message wasn't traslated properly.

lib/classes/task/manager.php

@@ -1116,7 +1116,7 @@ class manager {
 
         if (!self::is_runnable()) {
             $redirecturl = new \moodle_url('/admin/settings.php', ['section' => 'systempaths']);
-            throw new \moodle_exception('cannotfindthepathtothecli', 'core_task', $redirecturl->out());
+            throw new \moodle_exception('cannotfindthepathtothecli', 'tool_task', $redirecturl->out());
         } else {
             // Shell-escaped path to the PHP binary.
             $phpbinary = escapeshellarg(self::find_php_cli_path());