Better failure logging when loading initial data

[rolandgeider]

At the moment, if one of the requests/steps in _loadEntries() in home_tabs_screen.dart throws some exception (perhaps because some API response is not what was expected), the error is silently ignored. This causes the app to seemingly load correctly, but shows an empty dashboard

[rolandgeider]

See e.g. #168

[watcher6280]

@rolandgeider while not a fix for this bug, I added a PR that I think can help towards better logging it. Let me know your thoughts if you get some time.

[Dieterbe]

I believe the logging aspect of this was addressed in aecbcfe and 68f0ad4 , but we still have the issue of how we communicate failures back to the user.