System-level events should always be logged

[electricmonk]

Currently we only log errors in production.
We'd like to also log system events. These are events that happen during the init flow of the system, or major events that happen during runtime.

How:

1. Filters are defined in instrumentation/logger.go
2. Define a new log tag, "system" and add it to log calls during system startup
3. Go over major flows with the team and brainstorm about other info-level events we'd like to see logged