Replace UsageOverview visualization with metadata + single stats
## Background
This issue stems from the discussion in [#589575](https://gitlab.com/gitlab-org/gitlab/-/work_items/589575#note_3189399353) regarding visualization requirements for GLQL.
{width=900 height=158}
## Goals
This review aims to determine:
- If we plan to continue using this visualization
- Should we proceed with splitting the namespace information from the usage data
- Is the usage data visualization useful moving forward
## Related Links
- [Old Figma designs](https://www.figma.com/design/3OdxYMCcb11ml67RajawkD/Value-Stream-Dashboard--9317?node-id=5260-17624&t=Uo4fx0Lb3irYdHQf-0)
- https://gitlab.com/gitlab-org/gitlab/-/work_items/523473+
- https://gitlab.com/gitlab-org/gitlab/-/merge_requests/183096+
- https://gitlab.com/gitlab-org/gitlab/-/work_items/467997+
## Todo
- [x] [Create single stat visualizations for each of the usage metrics](https://gitlab.com/gitlab-org/gitlab/-/work_items/523473)
- [x] Split `UsageOverview` component into Metadata component and a new row of single stats
- [x] Update related configs + update ~documentation
issue