yum always return changes dict, not only in check mode (#51987)

Previously the yum module would provide a `changes` dict when
executed in check mode but omit it when not in check mode in favor
of the `results` data which is raw output from the yum command. This
pull request makes that output uniform.

Fixes #51724

Signed-off-by: Adam Miller <admiller@redhat.com>

changelogs/fragments/yum-consistent-output-checkmode.yaml

@@ -0,0 +1,2 @@
+minor_changes:
+  - yum - provide consistent return data structure when run in check mode and not in check mode