Move optional approval text to messages

**Why?**
These messages will be needed by the multiple approval rules component.

ee/app/assets/javascripts/vue_merge_request_widget/components/approvals/messages.js

@@ -7,3 +7,5 @@ export const FETCH_ERROR = s__(
 export const APPROVE_ERROR = s__('mrWidget|An error occurred while submitting your approval.');
 export const UNAPPROVE_ERROR = s__('mrWidget|An error occurred while removing your approval.');
 export const APPROVED_MESSAGE = s__('mrWidget|Merge request approved.');
+export const OPTIONAL_CAN_APPROVE = s__('mrWidget|No approval required; you can still approve');
+export const OPTIONAL = s__('mrWidget|No approval required');

ee/app/assets/javascripts/vue_merge_request_widget/components/approvals/single_rule/approvals_body.vue

@@ -5,7 +5,7 @@ import Icon from '~/vue_shared/components/icon.vue';
 import MrWidgetAuthor from '~/vue_merge_request_widget/components/mr_widget_author.vue';
 import tooltip from '~/vue_shared/directives/tooltip';
 import eventHub from '~/vue_merge_request_widget/event_hub';
-import { APPROVE_ERROR } from '../messages';
+import { APPROVE_ERROR, OPTIONAL_CAN_APPROVE, OPTIONAL } from '../messages';
 
 export default {
   name: 'ApprovalsBody',
@@ -65,10 +65,10 @@ export default {
     approvalsRequiredStringified() {
       if (this.approvalsOptional) {
         if (this.userCanApprove) {
-          return s__('mrWidget|No Approval required; you can still approve');
+          return OPTIONAL_CAN_APPROVE;
         }
 
-        return s__('mrWidget|No Approval required');
+        return OPTIONAL;
       }
 
       if (this.approvalsLeft === 0) {

ee/spec/javascripts/vue_mr_widget/components/approvals/single_rule/approvals_body_spec.js

 import Vue from 'vue';
 import ApprovalsBody from 'ee/vue_merge_request_widget/components/approvals/single_rule/approvals_body.vue';
+import {
+  OPTIONAL,
+  OPTIONAL_CAN_APPROVE,
+} from 'ee/vue_merge_request_widget/components/approvals/messages';
 
 describe('Approvals Body Component', () => {
   let vm;
@@ -62,7 +66,7 @@ describe('Approvals Body Component', () => {
       });
 
       it('should display the correct string for 0 approvals required', done => {
-        const correctText = 'No Approval required';
+        const correctText = OPTIONAL;
 
         vm.approvalsOptional = true;
 
@@ -73,7 +77,7 @@ describe('Approvals Body Component', () => {
       });
 
       it('should display the correct string for 0 approvals required and if the user is able to approve', done => {
-        const correctText = 'No Approval required; you can still approve';
+        const correctText = OPTIONAL_CAN_APPROVE;
 
         vm.approvalsOptional = true;
         vm.userCanApprove = true;

locale/gitlab.pot

@@ -11978,10 +11978,10 @@ msgstr ""
 msgid "mrWidget|Merged by"
 msgstr ""
 
-msgid "mrWidget|No Approval required"
+msgid "mrWidget|No approval required"
 msgstr ""
 
-msgid "mrWidget|No Approval required; you can still approve"
+msgid "mrWidget|No approval required; you can still approve"
 msgstr ""
 
 msgid "mrWidget|Open in Web IDE"