Update GitLab UI to latest version

See merge request gitlab-org/gitlab-ce!25428

(cherry picked from commit d5ab93a6)

67b2203b Update GitLab UI to latest version

Use gitlab-svg to provide the icons for rails, spring and express. For
the new GitLab pages templates, we are falling back to the GitLab logo.

- Use JS regex for emoji validation
- Add test for blocking emojis in full name
- Fix existing tests for user status that failed locally

v2.1.0 was published wrongly by the package author.

The schema is built on top of the default schema and Node and Mark
classes provided by tiptap-extensions. prosemirror-model is used to
parse HTML/DOM into a prosemirror document, and prosemirror-markdown is
used to serialize this document to (GitLab Flavored) Markdown.

https://babeljs.io/blog/2019/01/21/7.3.0

It seems like every new version of Chrome renders the favicon canvas
differently. This reduces the problems with it by creating a more fault
tolerant check, which compares the color values in the pixels and is
okay if they are within a certain threshold.

Upgrades prettier to 1.15.3
Runs `yarn prettier-save-all` against the codebase
Most changes are due to https://github.com/prettier/prettier/pull/5519

This reverts to 2.2.0, which has node@6 compatibility

This upgrades the following packages:
- Vue
- Vue Loader
- Vue Resource
- Vue Router
- Vue template compiler
- Vue Jest

Closes https://gitlab.com/gitlab-org/gitlab-ce/issues/53779

This danger check utilises `yarn-deduplicate` in order to show duplicate
dependencies in the yarn.lock dependency tree.
Often when introducing new dependencies or updating existing ones, yarn
does not seem to build the most optimal dependency tree.

In order to prevent those unnecessary dependency updates we are nudging
developers and maintainers to resolve these issues in MRs. Automating
this with danger especially helps, as yarn.lock files are not that easy
to review.