Removes the feature flag that controls whether
metrics dashboard urls unfurl the metrics dashboard
charts.

Changes migration and all other places the attribute is used

Adds an instance setting to limit display of time tracking
values to hours only

Adds EE information to gon
Creates a global vue mixin

After upgrading to Ruby 2.5.3, we switched `URI.join` in favor of
`Gitlab::Utils.append_path`. However,
ActionController::Base.helpers.image_path can return a full URL if a CDN
host is present.

Rails provides a way to generate the full URL using the asset path, but
that doesn't appear to work because `request` is nil`.

Revert to the previous behavior to handle CDNs and relative URLs.

Closes https://gitlab.com/gitlab-org/gitlab-ce/issues/56268

In Ruby 2.4, `URI.join("http://test//", "a").to_s` will
remove the double slash, however it's not the case in
Ruby 2.5. Using chomp should work better for the intention,
as we're not trying to allow things like ../ or / paths
resolution.

Closes https://gitlab.com/gitlab-org/gitlab-ce/issues/53180

This adds a method to Gitlab::GonHelper called
`push_frontend_feature_flag`. This method can be used to easily expose
the state of a feature flag to Javascript code. For example, using this
method we may write the following controller code:

    before_action do
      push_frontend_feature_flag(:vim_bindings)
    end

    def index
      # ...
    end

    def edit
      # ...
    end

In Javascript we can then check the state of the flag as follows:

    if ( gon.features.vimBindings ) {
      // ...
    }

Fixes https://gitlab.com/gitlab-org/release/framework/issues/17

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

Open the settings section based on the location hash

Prepares for i18n

The initializers including this were doing so at the top level, so every object
loaded after them had a `current_application_settings` method. However, if
someone had rack-attack enabled (which was loaded before these initializers), it
would try to load the API, and fail, because `Gitlab::CurrentSettings` didn't
have that method.

To fix this:

1. Don't include `Gitlab::CurrentSettings` at the top level. We do not need
   `Object.new.current_application_settings` to work.
2. Make `Gitlab::CurrentSettings` explicitly `extend self`, as we already use it
   like that in several places.
3. Change the initializers to use that new form.