Cells: Move `appearances` into `clusterwide`

What does this MR do and why?

• This table is configured from Admin Area and are cluster-wide.
• This uses a work already done for application_settings.
• A new mechanism is added to selectively ignore queries generated by uploads.
• The uploads problem are to be tracked separately.

Since this is accessed in isolation no future work is required to split joins.

References:

• related to: Cells: Iteration 1: Introduce attach `appearanc... (#397697 - closed)
• similar to: Pods: Iteration 1: Introduce `gitlab_main_clust... (#388275 - closed)
• similar to: Pods: Iteration 1: Introduce `ClusterMain::Appl... (#388276 - closed)

Follow-ups:

• Cells: Classify: Make `uploads` table to be att... (#398199)

How to set up and validate locally

GDK: Follow the process from: !109439 (merged)

GCK: Use this branch: gitlab-compose-kit!233 (merged) and follow the environment configuration.

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.