Expose active parameter to the Projects REST API

Expose the active parameter added in #525631 (closed) to the Projects REST API

Implementation Guide

After #525631 (closed) has been completed.

1. In /lib/api/projects.rb, add active as a new supported parameter.

optional :active, type: Boolean, desc: 'Limit by projects that are not archived. For Premium or Ultimate, projects that are marked for deletion are also filtered.'

2. Add the new parameter in the Projects API documentation in doc/api/projects.md
3. Add the corresponding test in /spec/requests/api/project_spec.rb and /ee/spec/requests/api/projects_spec.rb