Show a message if many levels are restricted and a
different message if all levels are restricted.

If the default, instance-wide visibility were set to internal but a
group were private, the radio button would be set on internal even
though that setting were not allowed. We now consider the allowed
visibility setting for the group in determining what the default should
be.

Closes https://gitlab.com/gitlab-org/gitlab-ce/issues/62298

- Update qa selector
- Update PO file

Continues the iteration on the project overview UI:

- moved star, fork and new clone button
(copy SSH/HTTPS URLs) to top right,
  made them smaller
- avatar is now larger (64px)
- 'Request access' is now a link instead
  of a button
- overview comes before the description +
  changed styling and added icons
- description font-size is now 16px (large-paragraph)
- quick links to files are moved downwards
  below the commit/pipeline info
- margins changed to group content into
  4 groups to clean up the interface
- visibility info reduced to icon-only and
  moved to the right of the title

Partially addresses #47424.

Adds a rubocop rule (with autocorrect) to ensure line break after guard clauses.

add notes to the disabled visibility setting string helper to ensure changes are reflected in the model as well

When a snippet is submitted, but there's an error, we didn't keep the
visibility level. As the default is private, this means that submitting
a public snippet that failed would then fall back to being a private
snippet.

Prevent Groups to have smaller visibility than projects
Add default_group_visibility_level to configuration
Code improvements

Add new global application settings for default project and snippet
visibility levels.

Fix a 500 error when the `restricted_visibility_levels` setting is null
in the database.

Add checkboxes to the application settings page for restricted
visibility levels, and remove those settings from gitlab.yml.