feat: Offline support

[techno-disaster]

Is your feature request related to a problem? Please describe.
As a user sometimes I'm not connected to the internet, I would like to still see my profile, tasks, stats when not connected to the internet

Describe the solution you'd like
Add offline support to the app wherein the data from each page is stored. For security reasons we will be encrypting it with AES 256 bit. Also when the user is offline show a small banner in the app-bar saying they are offline. If they pull down to refresh just load the data which we were able to successfully get from the back end.