Make all doc fragments, module utils, and plugin utils private (#1144)

* Make all doc fragments, module utils, and plugin utils private.

* Remove some unused and no longer needed imports.

This hopefully also fixes the CI issues, which do not happen locally for me...

* Fix formatting.

* Try to make CI happy, again.

* Fix imports.

* Lint.

plugins/modules/docker_compose_v2.py

@@ -19,11 +19,11 @@ version_added: 3.6.0
 description:
   - Uses Docker Compose to start or shutdown services.
 extends_documentation_fragment:
-  - community.docker.compose_v2
-  - community.docker.compose_v2.minimum_version
-  - community.docker.docker.cli_documentation
-  - community.docker.attributes
-  - community.docker.attributes.actiongroup_docker
+  - community.docker._compose_v2
+  - community.docker._compose_v2.minimum_version
+  - community.docker._docker.cli_documentation
+  - community.docker._attributes
+  - community.docker._attributes.actiongroup_docker
 
 attributes:
   check_mode:
@@ -439,16 +439,16 @@ actions:
 import traceback
 
 from ansible.module_utils.common.validation import check_type_int
-from ansible_collections.community.docker.plugins.module_utils.common_cli import (
+from ansible_collections.community.docker.plugins.module_utils._common_cli import (
     AnsibleModuleDockerClient,
     DockerException,
 )
-from ansible_collections.community.docker.plugins.module_utils.compose_v2 import (
+from ansible_collections.community.docker.plugins.module_utils._compose_v2 import (
     BaseComposeManager,
     common_compose_argspec_ex,
     is_failed,
 )
-from ansible_collections.community.docker.plugins.module_utils.version import (
+from ansible_collections.community.docker.plugins.module_utils._version import (
     LooseVersion,
 )