UI for dynamic worker pools

Part of #538 (closed)

As documented in https://freexian-team.pages.debian.net/debusine/reference/devel-blueprints/dynamic-compute.html#user-interface

To do:

• Add a indication to /-/status/workers/ showing each worker’s pool. (!1767 (merged))
• Exclude inactive dynamic workers from /-/status/workers/, to avoid flooding users with irrelevant information. (!1770 (merged))
• Make each worker on /-/status/workers/ be a link to a view for that single worker. Where available, that view includes information from the corresponding WorkerPool, excluding secret details of the provider account. (!1772 (merged))
• Link the worker view also from the sidebar of the work request detail view (!1775 (merged))
• Show a work request table in worker detail (!1775 (merged))
• Add a worker pool detail page with worker pool details and a pagination of workers (!1777 (merged))
• Removed /status/ prefix from workers and worker-pools urls (!1780 (merged))