Engine: UI: Initial code for Lifecycle Environment Paths page
Engine: Lifecycle Environment Paths: add to the Content navigation/menu

This is to make the new Lifecyle Environment Paths page available
from Content->Lifecycle Environment Paths.  This will not be needed
once we move to a single nav.
Engine: UI: Lifecycle Environments: updates as part of PR review

Updates based on PR feedback as well as other random cleanup.
Engine: UI: Lifecycle Environments: adding tests
Engine: test: regenerate vcr_cassettes

After adding several tests for environments, needed to regenerate
cassettes.
Merge pull request #3525 from bbuckingham/engine-environments

Engine: UI: Lifecycle Environment Paths UI