bpo-39791: Add files() to importlib.resources (GH-19722)

* bpo-39791: Update importlib.resources to support files() API (importlib_resources 1.5).

* 📜🤖 Added by blurb_it.

* Add some documentation about the new objects added.

Co-authored-by: blurb-it[bot] <43283697+blurb-it[bot]@users.noreply.github.com>

Lib/test/test_importlib/test_path.py

@@ -17,6 +17,7 @@ def test_reading(self):
         # Test also implicitly verifies the returned object is a pathlib.Path
         # instance.
         with resources.path(self.data, 'utf-8.file') as path:
+            self.assertTrue(path.name.endswith("utf-8.file"), repr(path))
             # pathlib.Path.read_text() was introduced in Python 3.5.
             with path.open('r', encoding='utf-8') as file:
                 text = file.read()