Add "paste embedded" to the context menu to paste images.

[bitboy85]

Is your feature request related to a problem? Please describe. No problem. Suggestion for improvement.

Describe the solution you'd like Adding "paste embedded" to the context menu. I guess most users will try the context menu to paste something, in this case an image which is in the clipboard. Currently "paste" is greyed out so it looks like that its not possible to paste an image. So i suggest to add "paste embedded" to this context menu.

Additional context First described here: https://github.com/ksnip/ksnip/issues/606

[DamirPorobic]

Sorry, forgot to mention that it should go in the annotator project.