Added Functional Tests for CSV Tuner Plugin (#1968)

* Add functional tests for CSV Tuner Plugin

* Updated directory structure

* Updated and renamed directories

* Updated csv conf files

* Updated readme

* Updated readme

* Updated readme

test/ext-plugins/pytest.ini

@@ -0,0 +1,12 @@
+# pytest.ini
+[pytest]
+markers =
+    ext_tuner: marks tests related to CSV Tuner Plugin
+    allreduce: marks tests related to AllReduce collective
+    broadcast: marks tests related to Broadcast collective
+    reduce: marks tests related to Reduce collective
+    allgather: marks tests related to AllGather collective
+    reducescatter: marks tests related to ReduceScatter collective
+    multinode: marks tests related to multi-node configuration
+
+testpaths = tests