app should persist the last selected category

[amwebexpert]

Actual behavior:

• one categories are retrieved from API call, the app default selection to the very first one

Expected behavior:

• each time a user pick a category, we should persist the selected one
• on app startup we should check if we have a persisted category, double check if it (still) exists and select it

[JefvdA]

Hey,

I'll work on this issue if that's fine.

[amwebexpert]

Great!