Add powerhub charging binary sensor and optional update intervals

[ItsRebaseTime]

Added PowerHub binary sensor just to make a bit cleaner way to get the charging status without parsing the text sensor in lambdas.

Also noticed that there are no update interval configuration options for the sensors, so added those too.

[parker-int64]

Thanks for the suggestion.

Refactoring the charge/vin status into a dedicated component was the right move. The original implementation focused on exposing raw register values, which—while technically accurate—is less relevant to the user than simply knowing the current state.

Although update_interval exist in pollingcomponent, somehow we are still using set_interval for each different sensors. (Different sensors may need different polling interval)

I'm thinking changing the structure to individual sub component.

[ItsRebaseTime]

@parker-int64 Could you give me a config yaml example of what you have in mind? I would be happy to do it