Deprecate Drupal utility scripts

[nigelgbanks]

We should be pushing for images that are by and large configured at build time or in the worst case by confd templates, and should not rely on running commands via docker exec. As it is unreliable and less predictable and requires a release of isle-buildkit for downstream consumers.

To that end:

• An audit should be done of all the scripts
• A deprecate notice should be raised (not sure how to do this as they are bash scripts, but it should go into the release notes at least).
• Update the documentation to describe a better method for applying configuration from environment variables (i.e. how sandbox does it).
• On a subsequent release, the scripts can then be removed.

For example:
https://github.com/Islandora-Devops/isle-buildkit/blob/d5e177dc50acf964925f59684b6988f25a2620e2/drupal/rootfs/etc/islandora/utilities.sh

Has many assumptions about modules configuration etc, and is used to mutate settings.php at run time.

Those scripts were born out of porting what Ansible did into Docker, a good first start, but it's time to move on from them.