Add monitoring (Splunk + Grafana + BlackBox) (MAPCO-4741)

[NivGreenstein]

We need to monitor our project as part of the MapColonies product standard. We need to make sure:

1. The app streams logs to Splunk.
2. Create Splunk alerts.
3. Create Dashboard in Grafana (based on Prometheus data).
4. Add Blackbox availability alerts.

[NivGreenstein]

Done with Mapcolonies Infra Team