- Modify GraphqlLogger to subclass JsonLogger
- Replace the single-line analyser with one that can log all the GraphQL
query related information in one place.
- Implement analyzer behavior with spec

Enabling GraphQL batch requests allows for multiple queries
to be sent in 1 request reducing the amount of requests
we send to the server.

Responses come come back in the same order as the queries were
provided.

58404 - add change log


58404 - add spec


58404 - add more spec to test depth 2


58404 - fix spec


58404 - fix rubocop


58404 - refactor the code by Bob's advice


58404 - revert changes of all_graphql_fields_for


58404 - change text only


58404 - fix rspec according to gitlab's standard


58404 - revert previous spec


58404 - fix rubocop

Extends existing graphql's tracer with opentracing measurements. Because
it also adds Tracing::Graphql class (for opentracing), it also renames
Graphql::Tracing class to Graphql::GenericTracing to minimize confusion
with similar class names.

An IntrospectionQuery required more
complexity points.

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.

It makes all Types::BaseField default to a complexity of 1.

Queries themselves now have limited complexity, scaled
to the type of user: no user, authenticated user, or an
admin user.

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.

Partially addresses #47424.

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.

- All definitions have been replaced by classes: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- Loaders have been replaced by resolvers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`).