Re-activate unit tests for PartialRealizationConfig

[robertbartel]

This issue tracks the reactivation of the unit tests for PartialRealizationConfig, added in #316 but marked as skipped.

PR #316 includes unit tests for the new PartialRealizationConfig class. However, some problems initially prevented the tests from functioning as needed. These problems relate to the dependency on the ngen-config package, and in part specifically to ngen-cal#34.

These tests passed locally after installing a manually patched version of ngen-config, adjusting example data files to comply with ngen-config syntax requirements, and fixing problems with PartialRealizationConfig uncovered by the tests. To allow the PR to proceed, for the time being, the committed code must skip the unit tests for PartialRealizationConfig, but we eventually need to activate those.