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/_mh/base.py

@@ -0,0 +1,97 @@
+# (c) 2020, Alexei Znamensky <russoz@gmail.com>
+# Copyright (c) 2020, Ansible Project
+# Simplified BSD License (see LICENSES/BSD-2-Clause.txt or https://opensource.org/licenses/BSD-2-Clause)
+# SPDX-License-Identifier: BSD-2-Clause
+
+# 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 typing as t
+
+from ansible.module_utils.basic import AnsibleModule
+
+from ansible_collections.community.general.plugins.module_utils._mh.deco import module_fails_on_exception
+from ansible_collections.community.general.plugins.module_utils._mh.exceptions import ModuleHelperException as _MHE
+
+
+class ModuleHelperBase:
+    module: dict[str, t.Any] | None = None  # TODO: better spec using t.TypedDict
+    ModuleHelperException = _MHE
+    _delegated_to_module: tuple[str, ...] = (
+        "check_mode",
+        "get_bin_path",
+        "warn",
+        "deprecate",
+        "debug",
+    )
+
+    def __init__(self, module=None):
+        self._changed = False
+
+        if module:
+            self.module = module
+
+        if not isinstance(self.module, AnsibleModule):
+            self.module = AnsibleModule(**self.module)
+
+    @property
+    def diff_mode(self):
+        return self.module._diff
+
+    @property
+    def verbosity(self):
+        return self.module._verbosity
+
+    def do_raise(self, *args, **kwargs) -> t.NoReturn:
+        raise _MHE(*args, **kwargs)
+
+    def __getattr__(self, attr):
+        if attr in self._delegated_to_module:
+            return getattr(self.module, attr)
+        raise AttributeError(f"ModuleHelperBase has no attribute '{attr}'")
+
+    def __init_module__(self):
+        pass
+
+    def __run__(self):
+        raise NotImplementedError()
+
+    def __quit_module__(self):
+        pass
+
+    def __changed__(self):
+        raise NotImplementedError()
+
+    @property
+    def changed(self) -> bool:
+        try:
+            return self.__changed__()
+        except NotImplementedError:
+            return self._changed
+
+    @changed.setter
+    def changed(self, value: bool) -> None:
+        self._changed = value
+
+    def has_changed(self):
+        raise NotImplementedError()
+
+    @property
+    def output(self):
+        raise NotImplementedError()
+
+    @module_fails_on_exception
+    def run(self):
+        self.__init_module__()
+        self.__run__()
+        self.__quit_module__()
+        output = self.output
+        if "failed" not in output:
+            output["failed"] = False
+        self.module.exit_json(changed=self.has_changed(), **output)
+
+    @classmethod
+    def execute(cls, module=None):
+        cls(module).run()