Support naming customization on helm chart resources, some resources may be renamed during upgrade

This is a new opt-in switch ``useStandardNaming``, for backwards compatibility, to leverage the standard naming convention, which allows full use of fullnameOverride and nameOverride in all resources.

Only the following resources will be renamed using default of ``useStandardNaming=false``:
- ConfigMap {release}-airflow-config to {release}-config
- Secret {release}-airflow-metadata to {release}-metadata
- Secret {release}-airflow-result-backend to {release}-result-backend

For existing installations, all your resources will be recreated with a new name and helm will delete previous resources.

This won't delete existing PVCs for logs used by statefulset/deployments, but it will recreate them with brand new PVCs.
If you do want to preserve logs history you'll need to manually copy the data of these volumes into the new volumes after
deployment. Depending on what storage backend/class you're using this procedure may vary. If you don't mind starting
with fresh logs/redis volumes, you can just delete the old pvcs that will be names, for example:

.. code-block:: bash

    kubectl delete pvc -n airflow logs-gta-triggerer-0
    kubectl delete pvc -n airflow logs-gta-worker-0
    kubectl delete pvc -n airflow redis-db-gta-redis-0

If you do not change ``useStandardNaming`` or ``fullnameOverride`` after upgrade, you can proceed as usual and no unexpected behaviours will be presented.
