Make database logs easier to search

[markdboyd]

Right now, there is no single field for filtering database logs ingested from CloudWatch

Acceptance Criteria

• Add a new field/tag that allows database logs to be returned
• Ensure tagging is consistent for all CloudWatch log groups
• Add CF service name as a field in the logs

[markdboyd]

This is almost done. Remaining work:

• Wait for Add aws broker tag log groups perm terraform-provision#1813 to be deployed through to production
• Make sure Reconcile log groups aws-broker#397 is deployed to prod
• Run the reconciliation job for log groups in production
• Run the reconciliation jobs for RDS resource tags in production

Once those steps are done, then tags on RDS resources (databases, parameter groups, and associated cloudwatch log groups) should be consistent. The tags being correct on the cloudwatch log groups is especially important, since that metadata is used to populate the @cf fields on the logs in OpenSearch.

There will also be a new tag field for @cf.service, which is the service instance name, which should make it easier for customers to query for database logs by the service name that they know