Add feature to copy image to clipboard

[Mithil467]

• Add option to copy image under Image menu.
• Add shortcut CTRL-C

We can use xclip to achieve this.
xclip -selection clipboard -t image/png -i /path/to/image.png

[rexdivakar]

Assign it to me i will work on it @Mithil467

[Mithil467]

Sure! @rexdivakar Make sure you follow the contributing guidelines.