Add `environment` drop down to Metrics dashboard

Metrics on the Operations tab are currently limited to only viewing the production environment. We should expose an option to allow you to select the environment you would like to view.

• The easiest way to do this, would be to simply make the existing environment name a dropdown. But we could consider alternatives to better align with our other workflows like tracing and logging environment selectors.
• Once implemented, the screen should default to the production environment, and if it doesn't exist the first alphabetical.

Design

It has a dropdown which allows users to selec the environment.