Make api.env.mode consistent

* use "developer" in Azure
* fix man page: "development" to "developer"
* list known modes in API bootstrap methods

Other values for mode are still supported to avoid breaking existing
installations.

Fixes: https://pagure.io/freeipa/issue/8313
Signed-off-by: Christian Heimes <cheimes@redhat.com>
Reviewed-By: Rob Crittenden <rcritten@redhat.com>

ipalib/config.py

@@ -561,6 +561,8 @@ class Env:
 
         # Merge in context config file and then default config file:
         mode = self.__d.get('mode')  # pylint: disable=no-member
+        # documented public modes: production, developer
+        # internal modes: dummy, unit_test
         if mode != 'dummy':
             self._merge_from_file(self.conf)
             self._merge_from_file(self.conf_default)