feat: Check permissions endpoint (#1389)

* feat: Check permissions endpoint

Allows FE to query backend for permission capabilities.
Batch requests supported

coderd/coderd.go

@@ -250,6 +250,8 @@ func New(options *Options) (http.Handler, func()) {
 					r.Put("/roles", api.putUserRoles)
 					r.Get("/roles", api.userRoles)
 
+					r.Post("/authorization", api.checkPermissions)
+
 					r.Post("/keys", api.postAPIKey)
 					r.Route("/organizations", func(r chi.Router) {
 						r.Post("/", api.postOrganizationsByUser)