Merge mscclpp-lang to mscclpp project (#442)

First step to merge msccl-tools into mscclpp repo. In this step will
move all msccl related code, pass the current tests and do some
necessary refactor.

Add `mscclpp.language` module
Add `_InstructionOptimizer` and `DagOptimizer` class to optimize the dag
Add `DagLower` to lower dag to intermediate representation 
Add documents for mscclpp.language
Remove msccl related code

python/test/configs/mscclpp_lang_test_config.json

@@ -0,0 +1,34 @@
+[
+    {
+        "filename": "allgather_barrier.py",
+        "args": ["8", "8"]
+    },
+    {
+        "filename": "allreduce_allpairs_packet.py",
+        "args": ["8", "8"]
+    },
+    {
+        "filename": "allreduce_allpairs_get.py",
+        "args": ["8", "8"]
+    },
+    {
+        "filename": "allreduce_allpairs.py",
+        "args": ["8", "8"]
+    },
+    {
+        "filename": "allreduce_ring.py",
+        "args": ["8", "8"]
+    },
+    {
+        "filename": "send_recv_packet.py",
+        "args": ["2"]
+    },
+    {
+        "filename": "send_recv_proxy.py",
+        "args": ["2"]
+    },
+    {
+        "filename": "allreduce_nvls.py",
+        "args": ["8", "2"]
+    }
+]

python/test/test_generate_mscclpp_lang_result.py

@@ -0,0 +1,47 @@
+# Copyright (c) Microsoft Corporation.
+# Licensed under the MIT License.
+
+import argparse
+import json
+from pathlib import Path
+import subprocess
+
+
+def run_examples(input_folder, configs, output_folder):
+    for config in configs:
+        file_name = config["filename"]
+        args = config["args"]
+
+        input_file_path = Path(input_folder) / file_name
+        # Strip the ".py" from the filename and add ".output"
+        base_file_name = file_name[:-3] if file_name.endswith(".py") else file_name
+        base_file_name = base_file_name.replace("/", "_")
+        output_file_path = Path(output_folder) / f"{base_file_name}.output"
+
+        # Construct the command to run the Python script
+        command = ["python3", str(input_file_path)] + args
+
+        # Run the command and capture output
+        with open(output_file_path, "w") as output_file:
+            result = subprocess.run(command, stdout=output_file, stderr=subprocess.STDOUT, text=True)
+
+        # Optional: Check the return code to handle errors
+        if result.returncode != 0:
+            print(f"Error running {file_name}. See {output_file_path} for details.")
+
+
+def main(input_folder, config_path, output_folder):
+    with open(config_path, "r") as f:
+        config = json.load(f)
+
+    Path(output_folder).mkdir(parents=True, exist_ok=True)
+    run_examples(input_folder, config, output_folder)
+
+
+if __name__ == "__main__":
+    parser = argparse.ArgumentParser(description="Process files according to a configuration and save the results.")
+    parser.add_argument("input_folder", type=str, help="Path to the folder containing the input files.")
+    parser.add_argument("config", type=str, help="Path to the configuration file.")
+    parser.add_argument("output_folder", type=str, help="Path to the folder where the processed files will be saved.")
+    args = parser.parse_args()
+    main(args.input_folder, args.config, args.output_folder)