Resolve "C_017_R1 Check that questions exist before loading static symptom check"

Closes #1292 (closed)

I used a toast here as well to be consistent with existing code. However, we should discuss toasts vs alerts in #1302

Please also see my MR updating error codes: https://git.recoverycat.de/recoverycat/rcc-knowledge-base/-/merge_requests/4

Testing:

1. Import MockRccPublicRuntimeConfigModule in PAT base features
2. Remove a question from starterQuestionConfigs
3. Simulate scanning a static QR code via https://localhost:4200/data?d=ewogICJwcmVDb25maWd1cmVkU3ltcHRvbUNoZWNrIjogInN0YXJ0ZXJfc3ltcHRvbV9jaGVjayIKfQ

Previous behavior: The scan success modal was shown Behavior now: No scan success modal, error toast instead