Add unit coverage for the WAL archive and restore-job decision helpers.
The tables pin the version-skew contract: when the operator sets the
decision it overrides both the Cluster annotation and, for archiving, the
on-disk marker file, while a nil decision (an operator that predates the
field) reproduces the previous annotation-based behavior.
Signed-off-by: Armando Ruocco <armando.ruocco@enterprisedb.com>
