feat(cli): add logs cmd (#21430)

This PR adds a command to view the provisioner and agent logs for a
given workspace.
Note: I did investigate using the existing `cliui` methods to tail the
logs but they are tailored to a very specific use-case.

Other changes:
- Adds `Agents` to `dbfake.WorkspaceResponse`
- Adds methods to generate provisioner and agent logs in `dbgen`

---------

Co-authored-by: Steven Masley <Emyrk@users.noreply.github.com>

docs/manifest.json

@@ -1436,6 +1436,11 @@
 							"description": "Unauthenticate your local session",
 							"path": "reference/cli/logout.md"
 						},
+						{
+							"title": "logs",
+							"description": "View logs for a workspace",
+							"path": "reference/cli/logs.md"
+						},
 						{
 							"title": "netcheck",
 							"description": "Print network debug information for DERP and STUN",