This reverts merge request !26569

Extends graphql's platform tracing class to observe duration
of graphql methods.

In graphql 1.8.11 is added prometheus class but it's not very useful
for us because it uses prometheus_exporter to export results.

- Show pipeline status, title, MR Status and project path
- Popover attached to gitlab flavored markdown everywhere, including:
  + MR/Issue Title
  + MR/Issue description
  + MR/Issue comments
  + Rendered markdown files

Previously GraphQL field authorization happened like this:

    class ProjectType
      field :my_field, MyFieldType do
        authorize :permission
      end
    end

This change allowed us to authorize like this instead:

    class ProjectType
      field :my_field, MyFieldType, authorize: :permission
    end

A new initializer registers the `authorize` metadata keyword on GraphQL
Schema Objects and Fields, and we can collect this data within the
context of Instrumentation like this:

    field.metadata[:authorize]

The previous functionality of authorize is still being used for
mutations, as the #authorize method here is called at during the code
that executes during the mutation, rather than when a field resolves.

https://gitlab.com/gitlab-org/gitlab-ce/issues/57828

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

defaultBranch and ciConfigPath should only be available to users with
the :download_code permission for the Project, as the respository might
be private.

When implementing the authorize check on these properties, it was
found that our current Graphql::Authorize::Instrumentation class does
not work with fields that resolve to subclasses of
GraphQL::Schema::Scalar, like GraphQL::STRING_TYPE.

After discussion with other Create Team members, it has been decided
that because the GraphQL API is not GA, to remove these properties from
ProjectType, and instead implement them as part of epic
https://gitlab.com/groups/gitlab-org/-/epics/711

Issue:
https://gitlab.com/gitlab-org/gitlab-ce/issues/55316

And add tests

And fix the tests so that it won't run into circular paths.

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

This suggests possibly related issues when the user types a title.

This uses GraphQL to allow the frontend to request the exact
data that is requires. We also get free caching through the Vue Apollo
plugin.

With this we can include the ability to import .graphql files in JS
and Vue files.
Also we now have the Vue test utils library to make testing
Vue components easier.

Closes #22071

By specifying `key`, we get a different lazy batch loader for each
repository, which means that accessing a lazy object from one repository
will only result in that repository's objects being fetched, not those
of other repositories, saving us some unnecessary Gitaly lookups.

Partially addresses #47424.

This whitelists all existing offenses for the various CodeReuse cops, of
which most are triggered by the CodeReuse/ActiveRecord cop.

This is mainly the setup of mutations for GraphQL. Including
authorization and basic return type-structure.

This adds Keyset pagination to GraphQL lists. PoC for that is
pipelines on merge requests and projects.

When paginating a list, the base-64 encoded id of the ordering
field (in most cases the primary key) can be passed in the `before` or
`after` GraphQL argument.

This adds a reusable way to expose permissions for a user to types in
GraphQL.

This allows the user to get a single MR nested in a GraphQL project
query.

Since we need the full path and the iid anyway, this makes more sense
than having a root query that needs the full path as well.

This was overridden in the fields where this resolver was used. So
this change is purely cosmetic.

- All definitions have been replaced by classes:
  http://graphql-ruby.org/schema/class_based_api.html
- Authorization & Presentation have been refactored to work in the
  class based system
- Loaders have been replaced by resolvers
- Times are now coersed as ISO 8601

By specifying a presenter for the object type, we can keep the logic
out of `GitlabSchema`.

The presenter gets initialized using the object being presented, and
the context (including the `current_user`).