[bitnami/phpbb] Add tests and publish using VIB

[joancafom]

Description of the change The main objective of this PR is to publish our Bitnami PhpBB Helm Chart using VMware Image Builder. In order to do that, several changes are included:

• Adding the asset to the publishing workflow
• Increasing the existing test coverage of the asset by adding Cypress tests.
• Increasing the existing test coverage of the asset by adding GOSS tests.

Benefits

• Ensuring higher quality of the Helm charts.
• Increased pool of assets completely handled by VMware Image Builder.

Possible drawbacks Automated tests could show to be potentially flaky.

Test results

Tested in https://github.com/joancafom/charts/pull/62

Checklist

• [X] Title of the pull request follows this pattern [bitnami/<name_of_the_chart>] Descriptive title
• [X] All commits signed off and in the agreement of Developer Certificate of Origin (DCO)