Today, users have to set up an OpAMP server to run with our clickstack OTel collector. Instead, we should allow users to disable OpAMP when they're using ClickHouse Cloud with the clickstack integration.
This can be determined by `OPAMP_SERVER_URL` not being defined by the user.
The end result is that a user can do
```
docker run \
-e CLICKHOUSE_ENDPOINT=${CLICKHOUSE_ENDPOINT} \
-e CLICKHOUSE_USER=default \
-e CLICKHOUSE_PASSWORD=${CLICKHOUSE_PASSWORD} \
-p 8080:8080 -p 4317:4317 -p 4318:4318 \
clickhouse/clickstack-otel-collector:latest
```
Ref: HDX-3300
We now store `createdBy` in the `Alert` document when the alert
is created. This new field references the `User` document of the
currently logged in user. The property is optional to support
existing alerts in the database.
This information is also displayed in various places where alert
details are displayed. Older documents without the new field should
display nothing, resulting in the existing UX.
