[Frontend] Add optional delay parameter to dialog service

Issue #1168

platform/commonUI/dialog/src/DialogService.js

@@ -200,6 +200,9 @@ define(
          * shown above a progress bar to indicate what's happening.
          * @property {number} progress a percentage value (1-100)
          * indicating the completion of the blocking task
+         * @property {boolean} delay adds a brief delay before loading
+         * the dialog. Useful for removing the dialog flicker when the
+         * conditions for displaying the dialog change rapidly.
          * @property {string} progressText the message to show below a
          * progress bar to indicate progress. For example, this might be
          * used to indicate time remaining, or items still to process.