Part of #12160

Create a package that can be called from either cli or coderd to fetch the following given a specific workspace and agent combination:

• Deployment information (DERP map, access URL, regions, version, etc)

• Deployment healthcheck

• Client connection info endpoint for agent

• Client netcheck results

• Workspace and agent details:

  • GET /workspaces/:id
  • GET /workspaceagents/id
  • Workspace template + version + params
  • Build log for current workspace build
  • Agent startup logs for given agent

• From agent endpoint over tailnet:

  • Agent manifest with sensitive data removed
  • Agent DERP map and connection flags both from memory and from agent endpoint
  • Agent stats
  • Agent magicsock HTML page
  • Client magicsock HTML page
  • Full agent log /tmp/coder-agent.log

The goal is to be able to fetch this information from either the client or from coderd:

• In order to have redundancy in case one fails
• In order to determine inconsistencies between client and coderd POV