GtkEntry: Sanitize multi-line paste data
If I copy-paste some multi-line text into File Chooser's GtkEntry, the resulting text in the GtkEntry is only the first line of the multi-line text.
Often I copy a title from Evince or from a website and try to paste the title into a Save Dialog or Rename Popover. But if the copied words are scattered across multiple lines (fx due to word wrapping), GtkEntry only uses the words of the first line, which is less useful.
Since GtkEntry cannot handle multi-line text, it would be nice if we could sanitize the multi-line text so it becomes one single line?