test: move a test to an appropriate test file
This patch introduce a new test file test-evolve-orphan-corner-cases.t
for tests which covers corner cases.
test: remove duplicated test
We have the test in test-evolve-orphan-split.t which is covering the same
case this test does. Also this test states that evolve shows some error in
split case, but now this is not the case we update to the top of splitted
csets.