Rename datasets-server to dataset-viewer in infra internals?

[severo]

Follow-up to #2650.

Is it necessary? Not urgent in any Case.

Some elements to review:

• [ ] https://github.com/huggingface/infra
• [ ] https://github.com/huggingface/infra-deployments
• [ ] docker image tags (https://hub.docker.com/r/huggingface/datasets-server-services-search -> https://hub.docker.com/r/huggingface/dataset-viewer-services-search)
• [ ] Helm chart name
• [ ] AWS parameters
• [ ] kubernetes namespaces
• [ ] Hub app names and tokens
• [ ] https://huggingface.co/datasets/huggingface/documentation-images/resolve/main/datasets-server
• [ ] buckets: hf-datasets-server-statics-test, hf-datasets-server-statics
• [ ] MongoDB databases
• [ ] BetterUptime
• [ ] shared directories (PARQUET_METADATA_CACHE_APPNAME)

[severo]

Closing for now, as #2666.