[DeepSpeed] decouple DeepSpeedConfigHF from Trainer (#11966)

* decouple DeepSpeedConfigHF from Trainer

* add LoggingLevel ctx manager; add new test

* cleanup

* add docs

* Apply suggestions from code review

Co-authored-by: Sylvain Gugger <35901082+sgugger@users.noreply.github.com>

* implemented suggested renames

* formatter workaround

Co-authored-by: Sylvain Gugger <35901082+sgugger@users.noreply.github.com>

src/transformers/testing_utils.py

@@ -26,6 +26,8 @@ from io import StringIO
 from pathlib import Path
 from typing import Iterator, Union
 
+from transformers import logging as transformers_logging
+
 from .file_utils import (
     is_datasets_available,
     is_faiss_available,
@@ -648,6 +650,26 @@ class CaptureLogger:
         return f"captured: {self.out}\n"
 
 
+@contextlib.contextmanager
+def LoggingLevel(level):
+    """
+    This is a context manager to temporarily change transformers modules logging level to the desired value and have it
+    restored to the original setting at the end of the scope.
+
+    For example ::
+
+        with LoggingLevel(logging.INFO):
+            AutoModel.from_pretrained("gpt2") # calls logger.info() several times
+
+    """
+    orig_level = transformers_logging.get_verbosity()
+    try:
+        transformers_logging.set_verbosity(level)
+        yield
+    finally:
+        transformers_logging.set_verbosity(orig_level)
+
+
 @contextlib.contextmanager
 # adapted from https://stackoverflow.com/a/64789046/9201239
 def ExtendSysPath(path: Union[str, os.PathLike]) -> Iterator[None]: