Improve usage of `dag_pipeline_tab` and `filter_pipelines_search`
What does this MR do?
This does the following changes:
- Follows our practices to always scope feature flags https://docs.gitlab.com/ee/development/feature_flags/development.html
- Adds a scope to
dag_pipeline_tab
andfilter_pipelines_search
- Fixes a missing DAG tab not being enabled by default
Conformity
Edited by 🤖 GitLab Bot 🤖