Replace tooltip in markdown component with gl-tooltip

app/assets/javascripts/vue_shared/components/markdown/header.vue

 <script>
 import $ from 'jquery';
-import Tooltip from '../../directives/tooltip';
+import { GlTooltipDirective } from '@gitlab-org/gitlab-ui';
 import ToolbarButton from './toolbar_button.vue';
 import Icon from '../icon.vue';
 
 export default {
-  directives: {
-    Tooltip,
-  },
   components: {
     ToolbarButton,
     Icon,
   },
+  directives: {
+    GlTooltip: GlTooltipDirective,
+  },
   props: {
     previewMarkdown: {
       type: Boolean,
@@ -147,7 +147,7 @@ export default {
           icon="table"
         />
         <button
-          v-tooltip
+          v-gl-tooltip
           aria-label="Go full screen"
           class="toolbar-btn toolbar-fullscreen-btn js-zen-enter"
           data-container="body"

app/assets/javascripts/vue_shared/components/markdown/toolbar_button.vue

 <script>
-import tooltip from '../../directives/tooltip';
-import icon from '../icon.vue';
+import { GlTooltipDirective } from '@gitlab-org/gitlab-ui';
+import Icon from '../icon.vue';
 
 export default {
   components: {
-    icon,
+    Icon,
   },
   directives: {
-    tooltip,
+    GlTooltip: GlTooltipDirective,
   },
   props: {
     buttonTitle: {
@@ -43,7 +43,7 @@ export default {
 
 <template>
   <button
-    v-tooltip
+    v-gl-tooltip
     :data-md-tag="tag"
     :data-md-select="tagSelect"
     :data-md-block="tagBlock"

changelogs/unreleased/replace-tooltip-in-markdown-component.yml

+---
+title: Replace tooltip in markdown component with gl-tooltip
+merge_request: 21989
+author: George Tsiolis
+type: other