Remove IDE component external_link

With [this MR][1] merged, this component
is no longer used.

[1]: https://gitlab.com/gitlab-org/gitlab/-/merge_requests/28705

app/assets/javascripts/ide/components/external_link.vue

-<script>
-import Icon from '~/vue_shared/components/icon.vue';
-
-export default {
-  components: {
-    Icon,
-  },
-  props: {
-    file: {
-      type: Object,
-      required: true,
-    },
-  },
-  computed: {
-    showButtons() {
-      return this.file.permalink;
-    },
-  },
-};
-</script>
-
-<template>
-  <div v-if="showButtons" class="pull-right ide-btn-group">
-    <a
-      :href="file.permalink"
-      :title="s__('IDE|Open in file view')"
-      target="_blank"
-      rel="noopener noreferrer"
-    >
-      <span class="vertical-align-middle">{{ __('Open in file view') }}</span>
-      <icon :size="16" name="external-link" class="vertical-align-middle space-right" />
-    </a>
-  </div>
-</template>

locale/gitlab.pot

@@ -10650,9 +10650,6 @@ msgstr ""
 msgid "IDE|Live Preview"
 msgstr ""
 
-msgid "IDE|Open in file view"
-msgstr ""
-
 msgid "IDE|Preview your web application using Web IDE client-side evaluation."
 msgstr ""
 
@@ -13906,9 +13903,6 @@ msgstr ""
 msgid "Open in Xcode"
 msgstr ""
 
-msgid "Open in file view"
-msgstr ""
-
 msgid "Open issues"
 msgstr ""
 

spec/javascripts/ide/components/external_link_spec.js

-import Vue from 'vue';
-import externalLink from '~/ide/components/external_link.vue';
-import createVueComponent from '../../helpers/vue_mount_component_helper';
-import { file } from '../helpers';
-
-describe('ExternalLink', () => {
-  const activeFile = file();
-  let vm;
-
-  function createComponent() {
-    const ExternalLink = Vue.extend(externalLink);
-
-    activeFile.permalink = 'test';
-
-    return createVueComponent(ExternalLink, {
-      file: activeFile,
-    });
-  }
-
-  afterEach(() => {
-    vm.$destroy();
-  });
-
-  it('renders the external link with the correct href', done => {
-    activeFile.binary = true;
-    vm = createComponent();
-
-    vm.$nextTick(() => {
-      const openLink = vm.$el.querySelector('a');
-
-      expect(openLink.href).toMatch(`/${activeFile.permalink}`);
-      done();
-    });
-  });
-});