Enable configuration of log formatting

[cbgbt]

Issue number:
Closes #493

Description of changes:
This provides the ability to specify log formatting options via helm. You can control:

• The log format of the messages
• Whether or not ANSI colors are enabled

See the updated README for more details

Testing done:
Launched a cluster with logging_ansi_enabled: "false" and logging_formatter: "full" and noted the logs:

[ec2-user@ip-10-0-0-27 bottlerocket-update-operator]$ kubectl logs brupop-agent-5cfsv
2023-08-08T05:55:58.598600Z  INFO apiserver::client::webclient: Created K8s API Server client using service port service_port=443
2023-08-08T05:55:58.695562Z  INFO run:create_shadow_if_not_exist:create_metadata_shadow: agent::agentclient: Brs has been created. brs_name="ip-192-168-68-199.us-west-2.compute.internal"

Then again with logging_formatter: "json":

[ec2-user@ip-10-0-0-27 bottlerocket-update-operator]$ kubectl logs brupop-agent-cmklc
{"timestamp":"2023-08-08T05:57:10.737628Z","level":"INFO","fields":{"message":"Created K8s API Server client using service port","service_port":"443"},"target":"apiserver::client::webclient"}

Terms of contribution:

By submitting this pull request, I agree that this contribution is dual-licensed under the terms of both the Apache License, version 2.0, and the MIT license.

[markusboehme]

🙌

[stmcginnis]

I have not deployed, but code review-wise everything looks good and the test coverage gives me confidence. ;)

[cbgbt]

^ I forgot to run clippy 😅

[stmcginnis]

I've had clippy point me at map way too often. :D