Provide rootNamespace to visualizations

What does this MR do and why?

Related to #386842 (closed), the usage overview chart should only be queried for a root namespace, initially this was manually done in the data_sources/usage_overview.js fetch method, but this does not allow us to reflect the correct name in the title of the panel.

Instead we should make the rootNamespace available to visualizations.

This MR:

• injects the root namespace name and fullpath into fetch objects, making it available for use in visualizations
• uses the correct name for the panel title (always the group root)
• updates the related jest and rspec tests

Screenshots or screen recordings

Screenshots are required for UI changes, and strongly recommended for all other merge requests.

Subgroup

Before - SubGroup	After - SubGroup

Project

Before - Project	After - Project

Group (No change)

Before - Group	After - Group

How to set up and validate locally

Enable the :group_analytics_dashboard_dynamic_vsd feature flag

Feature.enable(:group_analytics_dashboard_dynamic_vsd)

1. Make sure you have an ultimate license
2. Invoke the seed script: FILTER=vsd_overview_counts bundle exec rake db:seed_fu
3. Verify that count records are created in the console: Analytics::ValueStreamDashboard::Count.count
4. From the left sidebar, click the Analyze > Application analytics link (Not Analytics dashboards)
5. The group dashboard list should appear, select Value Stream Dashboard (should be the only option)

MR acceptance checklist

This checklist encourages us to confirm any changes have been analyzed to reduce risks in quality, performance, reliability, security, and maintainability.

• I have evaluated the MR acceptance checklist for this MR.

Related to #386842 (closed)