translation and property cleanup

- Caught a missing translation
- QAed that the following fns should refer directly to hidden-properties
  and not the larger umbrella of built-in-properties

src/main/frontend/components/block.cljs

@@ -1845,8 +1845,8 @@
   [config block]
   (let [properties (walk/keywordize-keys (:block/properties block))
         properties-order (:block/properties-order block)
-        properties (apply dissoc properties (property/built-in-properties))
-        properties-order (remove (property/built-in-properties) properties-order)
+        properties (apply dissoc properties (property/hidden-properties))
+        properties-order (remove (property/hidden-properties) properties-order)
         pre-block? (:block/pre-block? block)
         properties (if pre-block?
                      (let [repo (state/get-current-repo)

src/main/frontend/components/editor.cljs

@@ -177,7 +177,7 @@
      result
      {:on-chosen   chosen-handler
       :on-enter    non-exist-block-handler
-      :empty-placeholder   [:div.text-gray-500.pl-4.pr-4 "Search for a block"]
+      :empty-placeholder   [:div.text-gray-500.pl-4.pr-4 (t :editor/block-search)]
       :item-render (fn [{:block/keys [page uuid]}]  ;; content returned from search engine is normalized
                      (let [page (or (:block/original-name page)
                                     (:block/name page))

src/main/frontend/handler/editor.cljs

@@ -384,7 +384,7 @@
         block (update block :block/refs remove-non-existed-refs!)
         block (attach-page-properties-if-exists! block)
         new-properties (merge
-                        (select-keys properties (property/built-in-properties))
+                        (select-keys properties (property/hidden-properties))
                         (:block/properties block))]
     (-> block
         (dissoc :block/top?