nut: Encrypt upsd user passwords with age

Switching from Ansible Vault to age.

I've changed the `upsd.users` template somewhat in order to handle the
`password` property separately.  Now, items in the `nut_users` list
are objects with properties instead of lists of objects with properties.
The latter was done to support repeating options (`actions` and
`instcmds`), but that is more appropriately handled with lists of
values.

This value is encrypted with the following public key:

    age1c6swn9tm0502jd3e0yszfd4qd7lgx2nd9uk0hruuckhx7zpn3utqhau7mz

roles/nut/templates/upsd.users.j2

@@ -1,8 +1,15 @@
 {% for username, settings in nut_users.items() %}
 [{{ username }}]
-{% for setting in settings %}
-{% for key, value in setting|dictsort %}
-{{ key }} = {{ value }}
+{% if settings.password|d(none) is not none %}
+password = {{ settings.password | decrypt }}
+{% endif %}
+{% for action in settings.actions|d([]) %}
+actions = {{ action }}
 {% endfor %}
+{% for instcmds in settings.instcmds|d([]) %}
+instcmds = {{ instcmds }}
 {% endfor %}
+{% if not loop.last %}
+
+{% endif %}
 {% endfor %}