[Frotend] Make the splash screen useable

[filipe-varela]

When the app is launched, the splash screen is somewhat called, leaving the screen in plain dark. For a better UX and also to just not leaving the page in dark, the SplashScreen should be revamped to not only show the App or HS's logo, but also to implement some logic for retrieving data and use it to build future pages or update some local database of the app.