Support --name-prefix in drenv.test

With this we can create and test an environment using --name-prefix.
This is likely to needed in CI when we run multiple environments
concurrently on the same host (.e.g one per pr).

Example usage:

    (cd test && drenv start --nane-prefix pr123- envs/regional-dr.yaml)
    ramenctl deploy --nane-prefix pr123- test/envs/regional-dr.yaml
    ramenctl config --nane-prefix pr123- test/envs/regional-dr.yaml
    test/basic-test/run  --nane-prefix pr123- test/envs/regional-dr.yaml

Part-of: RamenDR#959
Signed-off-by: Nir Soffer <nsoffer@redhat.com>

test/drenv/test.py

@@ -44,6 +44,10 @@ def start(name, file, config_file="config.yaml"):
         action="store_true",
         help="Be more verbose.",
     )
+    parser.add_argument(
+        "--name-prefix",
+        help="Prefix profile names",
+    )
     parser.add_argument(
         "filename",
         help="Environment filename",