Ensure all tests run for each chart version

Summary

Tests in the gitlab package run using the latest chart version (chartVersions[0]) - example.

Conversely, tests in the controllers package run against each chart version:

• Function to get the chart version from the environment
• Log output printing the version in use

This effectively means that although we currently run 3 separate unit_test jobs (supposedly for each chart version), the tests are actually all running for only the latest chart version.

Acceptance criteria

• All relevant tests consider the CHART_VERSION environment variable rather than pinning to the latest chart version