Add type hints and type checking (#885)

* Enable basic type checking.

* Fix first errors.

* Add changelog fragment.

* Add types to module_utils and plugin_utils (without module backends).

* Add typing hints for acme_* modules.

* Add typing to X.509 certificate modules, and add more helpers.

* Add typing to remaining module backends.

* Add typing for action, filter, and lookup plugins.

* Bump ansible-core 2.19 beta requirement for typing.

* Add more typing definitions.

* Add typing to some unit tests.

plugins/modules/openssh_keypair.py

@@ -198,13 +198,15 @@ comment:
   sample: test@comment
 """
 
+import typing as t
+
 from ansible.module_utils.basic import AnsibleModule
 from ansible_collections.community.crypto.plugins.module_utils.openssh.backends.keypair_backend import (
     select_backend,
 )
 
 
-def main():
+def main() -> t.NoReturn:
 
     module = AnsibleModule(
         argument_spec=dict(