Add visibility level to project repository

CHANGELOG.md

app/assets/javascripts/project_new.js

app/assets/stylesheets/pages/projects.scss

app/controllers/projects_controller.rb

app/helpers/preferences_helper.rb

app/helpers/projects_helper.rb

app/models/project_feature.rb

app/policies/project_policy.rb

app/views/projects/_customize_workflow.html.haml

app/views/projects/_home_panel.html.haml

app/views/projects/_wiki.html.haml

app/views/projects/edit.html.haml

app/views/projects/issues/_issues.html.haml

app/views/projects/show.html.haml

...2180455_add_repository_access_level_to_project_feature.rb

db/schema.rb

spec/controllers/projects_controller_spec.rb

spec/factories/projects.rb

spec/features/projects/features_visibility_spec.rb

spec/lib/gitlab/import_export/safe_model_attributes.yml