feat: Move workspaces under organizations (#1109)

This removes split ownership for workspaces. They are now
a resource of organizations and have a designated owner,
which is a user.

This enables simple administration for commands like:
- `coder stop ben/dev`
- `coder build logs colin/arch`

or if we decide to allow administrators to access workspaces,
they could even SSH using this syntax: `coder ssh colin/dev`.

cli/gitssh_test.go

@@ -57,7 +57,7 @@ func TestGitSSH(t *testing.T) {
 		})
 		template := coderdtest.CreateTemplate(t, client, user.OrganizationID, version.ID)
 		coderdtest.AwaitTemplateVersionJob(t, client, version.ID)
-		workspace := coderdtest.CreateWorkspace(t, client, codersdk.Me, template.ID)
+		workspace := coderdtest.CreateWorkspace(t, client, user.OrganizationID, template.ID)
 		coderdtest.AwaitWorkspaceBuildJob(t, client, workspace.LatestBuild.ID)
 
 		// start workspace agent