Allow copy and pasting of image files.

[aztecbinaynay]

In a markdown cell, it would be super neat if I could put in pictures there by both copy and pasting an image and by selecting an image from any directories in my computer without the need for code. This would enable me to teach python programming in a more visual way.

[agoatboi]

Currently, there is an option to do this through the base64 encoding of the image. You would use the following in a markdown cell:

![](data:image/jpeg;base64,***Image base64 code***)

I would very much like if this were automatically done when pasting image content in a cell.

[DonJayamanne]

Duplicate of #5774, microsoft/vscode#119961