Disable default export rules

This is part of the work to implement the consensus reached in the
[RFC][1] to prefer named exports over defalt exports.

Future iterations will migrate existing default exports to named
exports.

The bulk of the changes in this commit were performed with the following
script:

```bash
set -u

changed-files()
{
    local trunk="origin/master"
    local file=
    local committed_files=$(git diff "$trunk"... --numstat \
        | awk '/\.(js|vue)$/{ print $3 }')
    local changed_files=$(git diff --numstat \
        | awk '/\.(js|vue)$/{ print $3 }')
    for file in ${committed_files[@]} ${changed_files[@]}; do
        if [ -f "$file" ]; then
            echo "$file"
        fi
    done
}

git grep -lz "import/prefer-default-export" -- '**/*.js' \
    | xargs -0 perl -0pi -e \
    "s/[^\n]*eslint-disable[^\n]*"\
"import\/prefer-default-export[^\n]*\n//mgs"

git grep -lz "rfcs/-/issues/20" -- '**/*.js' \
    | xargs -0 perl -0pi -e \
    "s/[^\n]*rfcs\/-\/issues\/20[^\n]*\n//mgs"

yarn prettier --write $(changed-files)
```

The script is [idempotent][2], to help make it easier to keep
up-to-date.

[1]: https://gitlab.com/gitlab-org/frontend/rfcs/-/issues/20
[2]: https://en.wikipedia.org/wiki/Idempotence

spec/frontend/helpers/jest_helpers.js

-/* eslint-disable import/prefer-default-export */
-
 /*
 @module

spec/frontend/helpers/locale_helper.js

-/* eslint-disable import/prefer-default-export */
-
 export const setLanguage = languageCode => {
   const htmlElement = document.querySelector('html');

spec/frontend/integrations/edit/mock_data.js

-// eslint-disable-next-line import/prefer-default-export
 export const mockIntegrationProps = {
   id: 25,
   activeToggleProps: {

spec/frontend/issue_show/helpers.js

-// eslint-disable-next-line import/prefer-default-export
 export const keyboardDownEvent = (code, metaKey = false, ctrlKey = false) => {
   const e = new CustomEvent('keydown');

spec/frontend/jobs/store/helpers.js

 import state from '~/jobs/store/state';
-// eslint-disable-next-line import/prefer-default-export
 export const resetStore = store => {
   store.replaceState(state());
 };

spec/frontend/mocks/mocks_helper.js

@@ -29,7 +29,6 @@ const getMockFiles = root => readdir.sync(root, { deep: MAX_DEPTH, filter: mockF
 const defaultSetMock = (srcPath, mockPath) =>
   jest.mock(srcPath, () => jest.requireActual(mockPath));
-// eslint-disable-next-line import/prefer-default-export
 export const setupManualMocks = function setupManualMocks(setMock = defaultSetMock) {
   prefixMap.forEach(({ mocksRoot, requirePrefix }) => {
     const mocksRootAbsolute = path.join(__dirname, mocksRoot);

spec/frontend/notes/helpers.js

-// eslint-disable-next-line import/prefer-default-export
 export const resetStore = store => {
   store.replaceState({
     notes: [],

spec/frontend/registry/shared/mocks.js

-// eslint-disable-next-line import/prefer-default-export
 export const $toast = {
   show: jest.fn(),
 };

spec/frontend/releases/stores/modules/list/helpers.js

 import state from '~/releases/stores/modules/list/state';
-// eslint-disable-next-line import/prefer-default-export
 export const resetStore = store => {
   store.replaceState(state());
 };

spec/frontend/reports/accessibility_report/mock_data.js

-// eslint-disable-next-line import/prefer-default-export
 export const mockReport = {
   status: 'failed',
   summary: {

spec/frontend/serverless/utils.js

-// eslint-disable-next-line import/prefer-default-export
 export const adjustMetricQuery = data => {
   const updatedMetric = data.metrics;

spec/frontend/vue_mr_widget/components/mock_data.js

-// eslint-disable-next-line import/prefer-default-export
 export const artifactsList = [
   {
     text: 'result.txt',

spec/frontend_integration/test_helpers/factories/commit.js

@@ -2,7 +2,6 @@ import { withValues } from '../utils/obj';
 import { getCommit } from '../fixtures';
 import { createCommitId } from './commit_id';
-// eslint-disable-next-line import/prefer-default-export
 export const createNewCommit = ({ id = createCommitId(), message }, orig = getCommit()) => {
   return withValues(orig, {
     id,

spec/frontend_integration/test_helpers/mock_server/graphql.js

@@ -16,6 +16,5 @@ const graphqlResolvers = {
   },
 };
-// eslint-disable-next-line import/prefer-default-export
 export const graphqlQuery = (query, variables, schema) =>
   graphql(graphqlSchema, query, graphqlResolvers, schema, variables);

spec/frontend_integration/test_helpers/utils/overclock_timers.js

@@ -31,7 +31,6 @@
  *
  * @param {Number} boost
  */
-// eslint-disable-next-line import/prefer-default-export
 export const useOverclockTimers = (boost = 50) => {
   if (boost <= 0) {
     throw new Error(`[overclock_timers] boost (${boost}) cannot be <= 0`);

yarn.lock

@@ -827,10 +827,10 @@
   resolved "https://registry.yarnpkg.com/@gitlab/at.js/-/at.js-1.5.5.tgz#5f6bfe6baaef360daa9b038fa78798d7a6a916b4"
   integrity sha512-282Dn3SPVsUHVDhMsXgfnv+Rzog0uxecjttxGRQvxh25es1+xvkGQFsvJfkSKJ3X1kHVkSjKf+Tt5Rra+Jhp9g==
-"@gitlab/eslint-plugin@3.2.0":
-  version "3.2.0"
-  resolved "https://registry.yarnpkg.com/@gitlab/eslint-plugin/-/eslint-plugin-3.2.0.tgz#e1780c2cab4c206e4900f2a1a4cf636f788182ea"
-  integrity sha512-3s28sQoGMgmwKtmVij7TjBDdW6fHiP4k6k6FWZdU6XZBJFwwA0JlU8PzYZRRTyY+pYed2u1jF06LHzv5YWNS2g==
+"@gitlab/eslint-plugin@4.0.0":
+  version "4.0.0"
+  resolved "https://registry.yarnpkg.com/@gitlab/eslint-plugin/-/eslint-plugin-4.0.0.tgz#7beba53dea74f458d92040a8b2652e4fd60a6cc7"
+  integrity sha512-Gba9HXwWOLAN+O2H8WmGNPZFQ410wiGFmhgDQ5Sx4ic/N1ymtwNen2pnsaWcw8KK/1vAB/rHNUhH4Xu/l/mfMg==
   dependencies:
     babel-eslint "^10.0.3"
     eslint-config-airbnb-base "^14.0.0"