[Enabler] [zos_mvs_raw] Changes to ensure tests portability (#1633)

* Add IDCAMS dataset creation

* Update most tests

* Fix list and concat tests

* Shorten IBM-1047 expected string in test

* Add changelog fragment

* Remove hardcoded var and renamed its replacement for clarity

* Fix pylint issues

Author: rexemin

changelogs/fragments/1633-zos_mvs_raw_tests_portability.yml

@@ -0,0 +1,4 @@
+trivial:
+  - test_zos_mvs_raw_func.py - Remove the use of hard coded dataset
+    names.
+    (https://github.com/ansible-collections/ibm_zos_core/pull/1633).