Displaying custom errors in the modal window when using flows

Summary Now when using "Run script" in threads, if you want to inform users about an error and terminate the process (filter) throw new Error() is used But error prints only for administrator. I propose to add an error return method from the code, so you can set your own header, text, and error code. Right now an unexpected error is displayed. You can also add a basic "inform user" operation Basic Example _No response_ Motivation Often there are additional checks in the threads and there is no way to report that his request has ended for such and such reason. Detailed Design There is already a mechanism to display a modal window on error, you need to give the possibility to display it from the flows Requirements List Must Have: • Method for displaying a modal window with an error from "Run Script" • Basic output operation with an error Should Have: • Ability to display not in the modal win…