Wrap state when iterating a domain in templates

[balloob]

Description:

When iterating over a domain in templates, it was not wrapped in the template state object.

Example template:

	{% for entity in states.sensor %}
		{{ entity.name }} is {{ entity.state_with_unit }}
	{% endfor %}

[mention-bot]

@balloob, thanks for your PR! By analyzing the history of the files in this pull request, we identified @fabaff, @lwis and @antsar to be potential reviewers.