MDL-58126 googledocs: Re-implement the google docs repo

Use latest REST API (v3) - but avoid the google client libraries
(too big, too much to update, not integrated with auth).

Part of MDL-58220

admin/tool/oauth2/settings.php

@@ -25,6 +25,6 @@
 defined('MOODLE_INTERNAL') || die;
 
 if ($hassiteconfig) {
-    $ADMIN->add('server', new admin_externalpage('oauth2', new lang_string('pluginname','tool_oauth2'),
+    $ADMIN->add('server', new admin_externalpage('oauth2', new lang_string('pluginname', 'tool_oauth2'),
          "$CFG->wwwroot/$CFG->admin/tool/oauth2/issuers.php"));
 }