[RFE] Credentials: show file's content when entering value to an upload/drag-drop textBox

Description of problem:
On the create/update credentials wizard, the user cannot know if the text that was uploaded/pasted to the upload/drag-drop textBox was uploaded correctly since the text displayed is "[Encrypted]" for any value

Suggestion:
Display the text when the user types/pasts/uploads new text.
It is more important to display the text when the user enters it manually