Work towards replacing recursive namespace queries with linear queries.
This commit tracks the path to each namespace, and future work will
replace recursive queries with queries that utilize this new column.

Defaults to disabled
See epic https://gitlab.com/groups/gitlab-org/-/epics/2158

This iterates all YAMLs, and fetches milestone
associated with the MR or Issue.

This also organises items of all YAMLs in a consistent
order.

Kamil Trzcińśki authored 4 years ago and Shinya Maeda committed 4 years ago

This uses existing `rspec` suite to generate YAML
definition from the existing feature flags usage
as seen in the FOSS.