Add the ability to set state / attributes with entity proxies

[zoe-codez]

Entity proxies will now emit state & attribute updates if assigned to. These happen via the rest api, and are not sync

function Example({ hass }: TServiceParams) {
  const entity = hass.entity.byId("binary_sensor.foo");
  async function MyWorkflow() {
    entity.state = "off";
    // wait for hass to confirm if that matters
    await entity.nextState();
    await sleep(1000);
    entity.state = "on";
  }
}