Exposing `Hyrax.config.derivative_services`

[jeremyf]

Prior to this commit, we had a somewhat opaque mechanism for overriding the candidate Hyrax::DerivativeService services. There is precedence on doing this (see NewspaperWorks) yet the configuration was not exposed during application generation nor as part of Hyrax::Configuration.

This change exposes the setting of the derivative services a primary concern of configuring a Hyrax application.

Related to #5866

@samvera/hyrax-code-reviewers

[dlpierce]

@jeremyf Can you rebase this on main? There is a commit you're missing that limits our redis version and should fix the failing build.