testsuite: add cross-rack partial cancel issue reproducer

Problem: there is no reproducer for the cross-rack partial cancel bug
observed on production clusters using JGF.

Add the reproducer and test for both low and lonodex policies with
various aggregate filter configurations.

Author: milroy

t/CMakeLists.txt

@@ -30,6 +30,7 @@ set(ALL_TESTS
   t1025-rv1-reload.t
   t1026-rv1-partial-release.t
   t1027-rv1-partial-release-brokerless-resources.t
+  t1028-rv1-partial-release-across-racks.t
   t2317-resource-shrink.t
   t3000-jobspec.t
   t3001-resource-basic.t