add support of environtment variable for tab & group

packages/node_modules/@node-red/runtime/lib/flows/Subflow.js

@@ -43,6 +43,54 @@ function evaluateInputValue(value, type, node) {
     return redUtil.evaluateNodeProperty(value, type, node, null, null);
 }
 
+/*!
+ * Get value of environment variable defined in group node.
+ * @param {String} group - group node
+ * @param {String} name - name of variable
+ * @return {Object} object containing the value in val property or null if not defined
+ */
+function getGroupSetting(node, group, flow, name) {
+    if (group) {
+        if (!name.startsWith("$parent.")) {
+            if (group.env) {
+                if (!group._env) {
+                    const envs = group.env;
+                    const entries = envs.map((env) => [env.name, env]);
+                    group._env = Object.fromEntries(entries);
+                }
+                const env = group._env[name];
+                if (env) {
+                    let value = env.value;
+                    const type = env.type;
+                    if ((type !== "env") || (value !== name)) {
+                        if (type === "env") {
+                            value = value.replace(new RegExp("\\${"+name+"}","g"),"${$parent."+name+"}");
+                        }
+                        try {
+                            const val = evaluateInputValue(value, type, node);
+                            return {
+                                val: val
+                            };
+                        }
+                        catch (e) {
+                            this.error(e);
+                            return null;
+                        }
+                    }
+                }
+            }
+        }
+        else {
+            name = name.substring(8);
+        }
+        if (group.g && flow) {
+            const parent = flow.getGroupNode(group.g);
+            return getGroupSetting(node, parent, flow, name);
+        }
+    }
+    return null;
+}
+
 /**
  * This class represents a subflow - which is handled as a special type of Flow
  */
@@ -370,6 +418,16 @@ class Subflow extends Flow {
             // name starts $parent. ... so delegate to parent automatically
             name = name.substring(8);
         }
+        const node = this.subflowInstance;
+        if (node.g) {
+            const group = this.getGroupNode(node.g);
+            const result = getGroupSetting(node, group, this, name);
+            if (result) {
+                return result.val;
+            }
+        }
+        
+
         var parent = this.parent;
         if (parent) {
             var val = parent.getSetting(name);