feat: Allow workspace resources to attach multiple agents (#942)

This enables a "kubernetes_pod" to attach multiple agents that
could be for multiple services. Each agent is required to have
a unique name, so SSH syntax is:

`coder ssh <workspace>.<agent>`

A resource can have zero agents too, they aren't required.

cli/workspaceshow.go

@@ -1,36 +1,13 @@
 package cli
 
 import (
-	"fmt"
-
 	"github.com/spf13/cobra"
-
-	"github.com/coder/coder/codersdk"
 )
 
 func workspaceShow() *cobra.Command {
 	return &cobra.Command{
 		Use: "show",
 		RunE: func(cmd *cobra.Command, args []string) error {
-			client, err := createClient(cmd)
-			if err != nil {
-				return err
-			}
-			workspace, err := client.WorkspaceByName(cmd.Context(), codersdk.Me, args[0])
-			if err != nil {
-				return err
-			}
-			resources, err := client.WorkspaceResourcesByBuild(cmd.Context(), workspace.LatestBuild.ID)
-			if err != nil {
-				return err
-			}
-			for _, resource := range resources {
-				if resource.Agent == nil {
-					continue
-				}
-
-				_, _ = fmt.Printf("Agent: %+v\n", resource.Agent)
-			}
 			return nil
 		},
 	}