Error handling

from https://github.com/nightscout/Trio-dev/commit/1e7b721896169abebf944372d89d4ea61dfbc3e1

Co-Authored-By: marv-out <107251660+marv-out@users.noreply.github.com>

Trio/Sources/Services/BolusCalculator/BolusCalculationManager.swift

@@ -192,8 +192,10 @@ final class BaseBolusCalculationManager: BolusCalculationManager, Injectable {
             fetchLimit: 288
         )
 
-        return await glucoseFetchContext.perform {
-            guard let fetchedResults = results as? [GlucoseStored] else { return [] }
+        return try await glucoseFetchContext.perform {
+            guard let fetchedResults = results as? [GlucoseStored] else {
+                throw CoreDataError.fetchError(function: #function, file: #file)
+            }
             return fetchedResults.map(\.objectID)
         }
     }