[FEATURE REQUEST] Access specific attributes of entity for secondary info

[craigmcfly]

When adding some secondary info, it would be good to be able to access all the attributes of an entity.

As an example, I tried to add a thermostat/climate entity and it just reads 0 (presumably because that's the numerical value of the first attribute). It would be good to be able to access the temperature attribute so that I can display it in the circle for that individual meter.