Internationalisation of raven directory

This is one of many MRs opened in order to improve the overall
internationalisation of the GitLab codebase.

This commit only targets Vanilla JS files.

i18n documentation
https://docs.gitlab.com/ee/development/i18n/externalization.html

app/assets/javascripts/raven/raven_config.js

 import Raven from 'raven-js';
 import $ from 'jquery';
+import { __ } from '~/locale';
 
 const IGNORE_ERRORS = [
   // Random plugins/extensions
@@ -9,9 +10,9 @@ const IGNORE_ERRORS = [
   'canvas.contentDocument',
   'MyApp_RemoveAllHighlights',
   'http://tt.epicplay.com',
-  "Can't find variable: ZiteReader",
-  'jigsaw is not defined',
-  'ComboSearch is not defined',
+  __("Can't find variable: ZiteReader"),
+  __('jigsaw is not defined'),
+  __('ComboSearch is not defined'),
   'http://loading.retry.widdit.com/',
   'atomicFindClose',
   // Facebook borked
@@ -80,7 +81,7 @@ const RavenConfig = {
 
   handleRavenErrors(event, req, config, err) {
     const error = err || req.statusText;
-    const responseText = req.responseText || 'Unknown response text';
+    const responseText = req.responseText || __('Unknown response text');
 
     Raven.captureMessage(error, {
       extra: {

locale/gitlab.pot

@@ -2061,6 +2061,9 @@ msgstr ""
 msgid "Can't find HEAD commit for this branch"
 msgstr ""
 
+msgid "Can't find variable: ZiteReader"
+msgstr ""
+
 msgid "Can't remove group members without group managed account"
 msgstr ""
 
@@ -2961,6 +2964,9 @@ msgstr ""
 msgid "Collapse sidebar"
 msgstr ""
 
+msgid "ComboSearch is not defined"
+msgstr ""
+
 msgid "Command line instructions"
 msgstr ""
 
@@ -12883,6 +12889,9 @@ msgstr ""
 msgid "Unknown format"
 msgstr ""
 
+msgid "Unknown response text"
+msgstr ""
+
 msgid "Unlimited"
 msgstr ""
 
@@ -14528,6 +14537,9 @@ msgstr ""
 msgid "it is too large"
 msgstr ""
 
+msgid "jigsaw is not defined"
+msgstr ""
+
 msgid "latest"
 msgstr ""