possible solution for issue #26028

Made some investigation:
- as written in my post, energy has a device_class and state_class power and current don't.
- searched for the reason why energy behaves different to power and current
- in [homeassistant.ts](https://github.com/Koenkk/zigbee2mqtt/blob/master/lib/extension/homeassistant.ts) I found this code in line 1018:
```
                // If a variable includes Wh, mark it as energy
                if (firstExpose.unit && ['Wh', 'kWh'].includes(firstExpose.unit)) {
                    Object.assign(extraAttrs, {device_class: 'energy', state_class: 'total_increasing'});
                }

```
I think a possible solution could be to add following
```
                // If a variable includes A or mA, mark it as energy
                if (firstExpose.unit && ['A', 'mA'].includes(firstExpose.unit)) {
                    Object.assign(extraAttrs, {device_class: 'current', state_class: 'measurement'});
                }

                // If a variable includes mW, W, kW, MW, GW, TW, mark it as energy
                if (firstExpose.unit && ['mW', 'W', 'kW', 'MW', 'GW', 'TW'].includes(firstExpose.unit)) {
                    Object.assign(extraAttrs, {device_class: 'power', state_class: 'measurement'});
                }

```
But I don't know how to test the changes in my homeassistant if that would fix the problem. Didn't found homeassistant.ts in my installation (using VS-Code-extension).
Perhaps it's also way for other sensors with other units, e.g. Data rate in bit/s, kbit/s, Mbit/s, Gbit/s, B/s, kB/s, MB/s, GB/s, KiB/s, MiB/s or GiB/s (see [here](https://www.home-assistant.io/integrations/sensor#device-class)).

lib/extension/homeassistant.ts

@@ -1020,6 +1020,16 @@ export default class HomeAssistant extends Extension {
                     Object.assign(extraAttrs, {device_class: 'energy', state_class: 'total_increasing'});
                 }
 
+                // If a variable includes A or mA, mark it as energy
+                if (firstExpose.unit && ['A', 'mA'].includes(firstExpose.unit)) {
+                    Object.assign(extraAttrs, {device_class: 'current', state_class: 'measurement'});
+                }
+
+                // If a variable includes mW, W, kW, MW, GW, TW, mark it as energy
+                if (firstExpose.unit && ['mW', 'W', 'kW', 'MW', 'GW', 'TW'].includes(firstExpose.unit)) {
+                    Object.assign(extraAttrs, {device_class: 'power', state_class: 'measurement'});
+                }
+
                 let key = firstExpose.name;
 
                 // Home Assistant uses a different voc device_class for µg/m³ versus ppb or ppm.