Add logger for Secure stage

We do not have any log messages from the application to track events like report parsing failures, usage of legacy reports, and other such scenarios because of which we have a limited view of the events happening in production (GitLab.com).

We can create our own structured Logger (as mentioned here https://docs.gitlab.com/ee/development/logging.html#how-to-use-json-logging) and use that throughout the Secure stage application code where need be.

Related discussion: #32862 and !17779 (comment 222703120)