Ensure extra env vars are propagated to remap command (#936)

*Issue #, if available:*

Fixes #848

*Description of changes:*

* Ensure the extra env vars are added to the remap launch command

### Testing 

Ran the [standalone
mode](https://graphstorm.readthedocs.io/en/v0.3/tutorials/quick-start.html)
example with extra parameter `--extra-envs
LD_LIBRARY_PATH="/opt/gs-venv/lib/python3.9/site-packages/dgl/:$LD_LIBRARY_PATH"`,
ensured that the command submitted by the launcher included the extra
env vars as:

```bash
cd /tmp/ogbn-arxiv-nc; (export LD_LIBRARY_PATH=/opt/gs-venv/lib/python3.9/site-packages/dgl/:; (export PYTHONPATH=/graphstorm/python/:/root/dgl/tools/::/root/dgl/python ; /opt/gs-venv/bin/python -m graphstorm.gconstruct.remap_result --cf /graphstorm/training_scripts/gsgnn_np/arxiv_nc.yaml --save-model-path /tmp/ogbn-arxiv-nc/models --save-embed-path /tmp/ogbn-arxiv-nc/embeddings --num-epochs 2 --ip-config /tmp/tmput45xgvc --part-config /tmp/ogbn_arxiv_nc_1p/ogbn-arxiv.json --rank 0 --world-size 1 --with-shared-fs True --num-processes 1 --output-chunk-size 100000 --preserve-input False))
```


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python/graphstorm/run/launch.py

@@ -776,7 +776,7 @@ def wrap_cmd_with_local_envvars(cmd: str, env_vars: str) -> str:
     return f"(export {env_vars}; {cmd})"
 
 
-def wrap_cmd_with_extra_envvars(cmd: str, env_vars: list) -> str:
+def wrap_cmd_with_extra_envvars(cmd: str, env_vars: List[str]) -> str:
     """Wraps a CLI command with extra env vars
 
     Example:
@@ -795,8 +795,7 @@ def wrap_cmd_with_extra_envvars(cmd: str, env_vars: list) -> str:
     Returns:
         cmd_with_env_vars:
     """
-    env_vars = " ".join(env_vars)
-    return wrap_cmd_with_local_envvars(cmd, env_vars)
+    return wrap_cmd_with_local_envvars(cmd, " ".join(env_vars))
 
 GLOBAL_GROUP_ID = 0
 
@@ -873,6 +872,11 @@ def submit_remap_jobs(args, udf_command, hosts, run_local):
                                                      args.preserve_input)
 
         cmd = wrap_cmd_with_local_envvars(remap_dist_command, env_vars)
+        cmd = (
+            wrap_cmd_with_extra_envvars(cmd, args.extra_envs)
+            if len(args.extra_envs) > 0
+            else cmd
+        )
 
         cmd = "cd " + str(args.workspace) + "; " + cmd
         clients_cmd.append(cmd)