1. Show PerDate widgets inside of an PageView
2. Introduce GoRouter so we can intercept back button taps with
BackButtonListener
3. Implement rudimentary navigation
4. Fix bug that still showed a spinner event when the barcode was not
found.
This fixes a bug that was caused by a name containing a comma.
We store the food entries in a csv so logically a comma in the name,
causes the parser to crash.
We fix this, by wrapping the name in quotation marks and writing a new
parser for food entries.
Now, an on-the-fly food lookup is created from existing entries on startup. Those entries are used to make suggestions when the user is typing to enter new food entries.
