Fix for unacknowledged numeric Z2M state updates

So far Z2M state updates were only boolean (the device `state` on/off),
but after introducing `brightness` values, Z2M state updates may not be
recognized/acknowledged. Unmarshalled Z2M numeric values are always
float64, but updates sent out via MQTT might not be. As a result, the
values may not directly equal and may never match.

To solve this, cast the outgoing expected value into a float64 to
compare against the received Z2M value, which is already a float64.

bridge.go

@@ -466,7 +466,10 @@ wait:
 			if BRIDGE_DEBUG {
 				log.Printf("received value %q (expected %q) for %s", updatedVal, expVal, key)
 			}
-			if updatedVal == expVal {
+			if updatedVal == expVal ||
+				// updatedVal is float64 coz that's how Z2M JSON values are, but expVal may not be
+				mapping.ExposesEntry.Type == "numeric" && cmpFloat64Numeric(updatedVal, expVal) {
+
 				updated = true
 				break wait
 			}
@@ -485,6 +488,17 @@ wait:
 	return updated, err
 }
 
+// Compare float64 f to numeric value n
+// Both parameters are marked as `any`. f will be type-asserted to float64,
+// whereas n will be converted to float64 before doing the comparison.
+func cmpFloat64Numeric(f, n any) bool {
+	if ff, ok := f.(float64); ok {
+		nn, ok := valToFloat64(n)
+		return ff == nn && ok
+	}
+	return false
+}
+
 // Publish to the MQTT broker for the specific device
 func (br *Bridge) PublishState(dev *Device, payload map[string]any) error {
 	topic := MQTT_TOPIC_PREFIX + dev.FriendlyName + "/set"