Feat: update postgresql dependency to use ironbank image

Description

Updating the values for postgresql dependency to include an ironbank approved image, as well as modifications to securityContexts to allow that container image to properly run.

The volumePermissions block was added in a default disabled state to allow stubbing in the big-bang/base image in the event that the existing persistent data needs to have the permissions and ownership modified.

Important

A note such as this will want to be created on the next release to inform anyone using this dependency what will be covered by upgrades vs other manual migrations.

Closes #54 (closed)