Upgrades prettier to the latest version, and auto-corrects files with
yarn prettier-all-save

The diffs all seem to stem from formatting changes in brackets within
template literals. Nothing major.

Relevant changelogs here:

https://prettier.io/blog/2019/04/12/1.17.0.html
https://prettier.io/blog/2019/06/06/1.18.0.html

This is one of many MRs opened in order to improve the overall
internationalisation of the GitLab codebase.

This commit only targets Vanilla JS files.

i18n documentation
https://docs.gitlab.com/ee/development/i18n/externalization.html

Wraps all imports for select 2 to deferred imports,
especially in the main.js we are actually checking if there 
is any select 2 element on the page or not.

Removes set favicon related methods from global scope
Improves test related with favicon

Removes convertPermissionToBoolean from global scope.
Adds tests for convertPermissionToBoolean - were non existant

Removes setParamInURL from gl.utils

Removes parseIntPagination from gl.utils namespace

Remove normalizeCRLFHeaders from gl.utils namespace

Removes normalizeHeaders from gl.utils namespace

Use gl.utils for filtered search

Fix bad import

Fix broken test by cleaning window.history namespace

Adds changelog

Closes https://gitlab.com/gitlab-org/gitlab-ee/issues/3149

Signed-off-by: Dmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>

Signed-off-by: Rémy Coutable <remy@rymai.me>