GUI:add favourite option

[lohani2280]

creates a favourite_pics folder inside .uip directory which save user's fav wallpaper and also immunes them against flush action. Fixes #121

[abhay-raizada]

Hi thank you for your Patch make sure you have the right commit structure that is

tag: Shortlog

body
Fixes <issue number/url>

[nemani]

Good work! :+1: Waiting for @abhsag24, and @nkprince007, they might have some suggestions to add

[abhay-raizada]

@lohani2280 can we have a screenshot of the feautre in action! looks awesome! :D

[lohani2280]

[lohani2280]