feat: Add endpoint to get all workspaces a user can access (#1354)

This iterates through user organizations to get permitted
workspaces. This will allow admins to manage user workspaces!

coderd/coderd.go

@@ -258,6 +258,7 @@ func New(options *Options) (http.Handler, func()) {
 					})
 					r.Get("/gitsshkey", api.gitSSHKey)
 					r.Put("/gitsshkey", api.regenerateGitSSHKey)
+					r.Get("/workspaces", api.workspacesByOwner)
 				})
 			})
 		})