☑️ Add test to clarify expected configuration

[jeremyf]

With Knapsack, we're noticing that load path issues can be a subtle problem.

With this commit, I'm testing the configuration to ensure that we have the expected and correct lamba for generating IIIF Page's file titles.

Related to:

• https://github.com/scientist-softserv/adventist_knapsack/issues/243