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>

cli/testdata/coder_--help.golden

@@ -28,6 +28,7 @@ SUBCOMMANDS:
     list              List workspaces
     login             Authenticate with Coder deployment
     logout            Unauthenticate your local session
+    logs              View logs for a workspace
     netcheck          Print network debug information for DERP and STUN
     notifications     Manage Coder notifications
     open              Open a workspace