Make search more error resistant and provide more information

[steffenkleinle]

Is your feature request related to a problem? Please describe.
At the moment, the search in Landkreis Ostallgäu is broken. This is due to minisearch failing if two items have the same id (in our case path). While this should not happen in general and be fixed in the CMS, the app should also not just fail/load forever without any error message.

Describe the solution you'd like

• Provide better errors if the search fails to the users (display an error message instead of endless loading spinner)
• Provide better errors for devs (log full errors to the console)
• Make the search more error resistant by removing items with duplicated id (optional/TBD)

Describe alternatives you've considered
Do nothing as this is not an app issue.

Additional context
Event in question: http://integreat.app/ostallgaeu/de/events/handarbeits-werkstatt-mit-begegnung-und-austausch-5