Make uncomplicated modules private (#7528)

* Create _internal package for Certbot's non-public modules

* Move account.py to _internal

* Move auth_handler.py to _internal

* Move cert_manager.py to _internal

* Move client.py to _internal

* Move error_handler.py to _internal

* Move lock.py to _internal

* Move main.py to _internal

* Move notify.py to _internal

* Move ocsp.py to _internal

* Move renewal.py to _internal

* Move reporter.py to _internal

* Move storage.py to _internal

* Move updater.py to _internal

* update apache and nginx oldest requirements

* Keep the lock file as certbot.lock

* nginx oldest tests still need to rely on newer certbot

* python doesn't have good dependency resolution, so specify the transitive dependency

* update required minimum versions in nginx setup.py

certbot-apache/certbot_apache/configurator.py

@@ -2345,7 +2345,7 @@ class ApacheConfigurator(common.Installer):
         Enable the AutoHSTS enhancement for defined domains
 
         :param _unused_lineage: Certificate lineage object, unused
-        :type _unused_lineage: certbot.storage.RenewableCert
+        :type _unused_lineage: certbot._internal.storage.RenewableCert
 
         :param domains: List of domains in certificate to enhance
         :type domains: str
@@ -2470,7 +2470,7 @@ class ApacheConfigurator(common.Installer):
         and changes the HSTS max-age to a high value.
 
         :param lineage: Certificate lineage object
-        :type lineage: certbot.storage.RenewableCert
+        :type lineage: certbot._internal.storage.RenewableCert
         """
         self._autohsts_fetch_state()
         if not self._autohsts: