Add DFS with parent-completion constraint for DAG traversal (#6467)

* Add DFS with parent-completion constraint for DAG traversal

* warning in PartitionProblem.java affecting tests

* added clang-format and updated javadoc

* optimized imports and rechecked camelCase format in tests

* removed .* import and made small visual change

* replaced a inline return with correct {} block

* Removed changed in PartitionProblem.java, Renamed class name to be straightforward about the implementation.Added full names instead of shortcuts, and included record.

* updated for clang format

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Co-authored-by: Deniz Altunkapan <93663085+DenizAltunkapan@users.noreply.github.com>