Update logic to process domain data (project-chip#1442)

- Added support to process domain data parsed from XML in both formats:
<domain>General</domain> and <domain name="General"/>
- The plan to update ZAP XMLs using Alchemy will require this change, as domain definitions will be updated to the format <domain name="General">

src-electron/zcl/zcl-loader-silabs.js

@@ -451,7 +451,13 @@ function prepareCluster(cluster, context, isExtension = false) {
     ret.name = cluster.name[0]
     ret.description = cluster.description ? cluster.description[0].trim() : ''
     ret.define = cluster.define[0]
-    ret.domain = cluster.domain[0]
+    // handle domain data parsed from both formats:
+    // <domain>General</domain> and <domain name="General"/>
+    if (cluster.domain[0] && cluster.domain[0].$) {
+      ret.domain = cluster.domain[0].$.name
+    } else {
+      ret.domain = cluster.domain[0]
+    }
     ret.isSingleton = false
     if ('$' in cluster) {
       if (cluster.$.manufacturerCode == null) {