✨ Add verify macro for true runtime spec asserts.

This commits mainly renames the old `assert` to `verify` and
adds new `assert` that laverages `:elide-asserts` on clojurescript
and *assert* value on clojure.

This approach enables an assert macro that does not performs
any runtime checks and compiles to more performant code in both
cases: development mode and production mode.

backend/src/uxbox/tasks/gc.clj

@@ -39,7 +39,7 @@
 (defn- delete-project
   "Clean deleted projects."
   [{:keys [id] :as props}]
-  (us/assert ::delete-project props)
+  (us/verify ::delete-project props)
   (db/with-atomic [conn db/pool]
     (-> (db/query-one conn [sql:delete-project id])
         (p/then (constantly nil)))))

backend/src/uxbox/tasks/impl.clj

@@ -266,7 +266,7 @@
 
 (defn schedule!
   [conn {:keys [name delay props queue key] :as options}]
-  (us/assert ::task-options options)
+  (us/verify ::task-options options)
   (let [queue (if (string? queue) queue "default")
         duration (-> (tm/duration delay)
                      (duration->pginterval))