Ability to set entity icon through mqtt discovery

The existing mqtt discovery component already allows you to specify the icon for switches and sensors, but that configuration variable is missing for lights.

Use case: Using zwave2mqtt I’d like to set the icon to mdi:coach-light, or mdi:dome-light within the discovery payload, much like we can set sensor and switch icons via. the same means. This means zero mqtt overrides need to exist within home assistant and nothing is lost on mqtt discover update changes.

Thank you