Add `createLabelTitle` & `manageLabelsTitle` props for action string

app/assets/javascripts/vue_shared/components/sidebar/labels_select/dropdown_footer.vue

 <script>
+import { __ } from '~/locale';
+
 export default {
   props: {
     labelsWebUrl: {
       type: String,
       required: true,
     },
+    createLabelTitle: {
+      type: String,
+      required: false,
+      default: () => __('Create new label'),
+    },
+    manageLabelsTitle: {
+      type: String,
+      required: false,
+      default: () => __('Manage labels'),
+    },
   },
 };
 </script>
@@ -17,7 +29,7 @@ export default {
           href="#"
           class="dropdown-toggle-page"
         >
-          {{ __('Create new label') }}
+          {{ createLabelTitle }}
         </a>
       </li>
       <li>
@@ -26,7 +38,7 @@ export default {
           class="dropdown-external-link"
           :href="labelsWebUrl"
         >
-          {{ __('Manage labels') }}
+          {{ manageLabelsTitle }}
         </a>
       </li>
     </ul>

spec/javascripts/vue_shared/components/sidebar/labels_select/dropdown_footer_spec.js

@@ -6,15 +6,23 @@ import { mockConfig } from './mock_data';
 
 import mountComponent from '../../../../helpers/vue_mount_component_helper';
 
-const createComponent = (labelsWebUrl = mockConfig.labelsWebUrl) => {
+const createComponent = (
+  labelsWebUrl = mockConfig.labelsWebUrl,
+  createLabelTitle,
+  manageLabelsTitle,
+) => {
   const Component = Vue.extend(dropdownFooterComponent);
 
   return mountComponent(Component, {
     labelsWebUrl,
+    createLabelTitle,
+    manageLabelsTitle,
   });
 };
 
 describe('DropdownFooterComponent', () => {
+  const createLabelTitle = 'Create project label';
+  const manageLabelsTitle = 'Manage project labels';
   let vm;
 
   beforeEach(() => {
@@ -26,17 +34,35 @@ describe('DropdownFooterComponent', () => {
   });
 
   describe('template', () => {
-    it('renders `Create new label` link element', () => {
+    it('renders link element with `Create new label` when `createLabelTitle` prop is not provided', () => {
       const createLabelEl = vm.$el.querySelector('.dropdown-footer-list .dropdown-toggle-page');
       expect(createLabelEl).not.toBeNull();
       expect(createLabelEl.innerText.trim()).toBe('Create new label');
     });
 
-    it('renders `Manage labels` link element', () => {
+    it('renders link element with value of `createLabelTitle` prop', () => {
+      const vmWithCreateLabelTitle = createComponent(mockConfig.labelsWebUrl, createLabelTitle);
+      const createLabelEl = vmWithCreateLabelTitle.$el.querySelector('.dropdown-footer-list .dropdown-toggle-page');
+      expect(createLabelEl.innerText.trim()).toBe(createLabelTitle);
+      vmWithCreateLabelTitle.$destroy();
+    });
+
+    it('renders link element with `Manage labels` when `manageLabelsTitle` prop is not provided', () => {
       const manageLabelsEl = vm.$el.querySelector('.dropdown-footer-list .dropdown-external-link');
       expect(manageLabelsEl).not.toBeNull();
       expect(manageLabelsEl.getAttribute('href')).toBe(vm.labelsWebUrl);
       expect(manageLabelsEl.innerText.trim()).toBe('Manage labels');
     });
+
+    it('renders link element with value of `manageLabelsTitle` prop', () => {
+      const vmWithManageLabelsTitle = createComponent(
+        mockConfig.labelsWebUrl,
+        createLabelTitle,
+        manageLabelsTitle,
+      );
+      const manageLabelsEl = vmWithManageLabelsTitle.$el.querySelector('.dropdown-footer-list .dropdown-external-link');
+      expect(manageLabelsEl.innerText.trim()).toBe(manageLabelsTitle);
+      vmWithManageLabelsTitle.$destroy();
+    });
   });
 });