docs(docker): update examples for running Zebra in Docker

[upbqdn]

Motivation

Update our Docker docs to reflect the changes in #8923.

Solution

• Update the Docker chapter in the Zebra book.
  • Add information on configuring Zebra, enabling the RPC server, and disabling the cookie authentication.
  • Add information on running Zebra with Prometheus and Grafana.
• Update the chapter on mining with Zebra in Docker.
• Prepare a new docker/.env file.
• Prepare a new docker/test.env file.
• Rename default_zebra_conf.toml to default-zebra-conf.toml.
• Make the cookie authentication easily configurable.
• Add a new docker compose file for running Zebra with Prometheus and Grafana.
• Update the default docker compose file.
• Update the docker compose file for running Zebra with lwd.
• Update the docker compose file for running CI tests locally.
• Fix a bug where the entrypoint would try to write to a mounted config file. The fix consists of copying the config file to a new location in the container and then writing to it. This change made the CI tests that check the loading of custom conf files fail because they were relying on file paths. I updated them so they check the content of the loaded conf file.

Tests

• Locally tested all commands stated in the updated docs.
• Locally tested all docker compose files.

PR Author's Checklist

• The PR name will make sense to users.
• The PR provides a CHANGELOG summary.
• The solution is tested.
• The documentation is up to date.
• The PR has a priority label.

PR Reviewer's Checklist

• The PR Author's checklist is complete.
• The PR resolves the issue.

[gustavovalverde]

This is great @upbqdn. Thank you!!