Rename environment variable EE to IS_GITLAB_EE

Closes #60080

See merge request gitlab-org/gitlab-ce!27044

Add columns to store project creation settings

Add project creation level column in groups
 and default project creation column in application settings

Remove obsolete line from schema

Update migration with project_creation_level column existence check

Rename migrations to avoid conflicts

Update migration methods

Update migration method

The api will proxy requests to the environment's prometheus server.
The Prometheus::ProxyService class can be reused when we add support for
group prometheus servers.

GraphQL Type authorization

Closes #54417

See merge request gitlab-org/gitlab-ce!25724

This prevents `&mdash` in our templates being change to `-`

Enables authorizations to be defined on GraphQL Types.

    module Types
      class ProjectType < BaseObject
        authorize :read_project
      end
    end

If a field has authorizations defined on it, and the return type of the
field also has authorizations defined on it. then all of the combined
permissions in the authorizations will be checked and must pass.

Connection fields are checked by "digging" to find the type class of the
"node" field in the expected location of edges->node.

Closes https://gitlab.com/gitlab-org/gitlab-ce/issues/54417

Loads 'Gitlab::Jira::Middleware' only if it exists
so this initializer can be backported to CE.