Now that all test reports have issue_id column populated
we can deprecate its relatioships with requirements and use
work items(issues of requirement type).
Requirements objects will only be used as proxy to keep its
iids compatible.

Changelog: changed
EE: true

Validate last_test_report_state parameter used
to filter requirements.

Allow to filter requirementsby  passed or failed
status on graphql.

The plan for RSpec 4.0 is to disable monkey patching:
https://rspec.info/blog/2013/07/the-plan-for-rspec-3/#zero-monkey-patching-mode

This commit stops using RSpec monkey patching:
https://relishapp.com/rspec/rspec-core/docs/configuration/zero-monkey-patching-mode

- Add scopes to Requirement, plus tests
- Add filters to RequirementsFinder, plus tests
- Add filter args to GraphQL resolver, plus tests

* moved under requirement_management

Allows listing requirements through GraphQL API and use basic
filtering and sorting parameters.