Please add 'attribute_templates' to Template Vacuum (and other templates that are missing it)

I would like to see the ability to use attribute_templates on any template that is configured, specifically the template vacuum would be a great start.

As documented here with the template sensor, keeping all the templates feature parity with each other.

Decided to do it myself.

This allows attribute_templates to be assigned to template vacuums now. Hopefully I can get it merged at some point.

Just trying to get the tests to work correctly, then a review…

Tests pass, just waiting on a dev to review.