Make all doc fragments, module utils, and plugin utils private (#11896)

* Make all doc fragments private.

* Make all plugin utils private.

* Make all module utils private.

* Reformat.

* Changelog fragment.

* Update configs and ignores.

* Adjust unit test names.

plugins/module_utils/_stormssh.py

@@ -4,6 +4,9 @@
 # Copyright (C) <2013> <Emre Yilmaz>
 # SPDX-License-Identifier: MIT
 
+# Note that this module util is **PRIVATE** to the collection. It can have breaking changes at any time.
+# Do not use this from other collections or standalone plugins/modules!
+
 from __future__ import annotations
 
 import os