Fix security group compression (#3410)

* Fix security group compression.
Improved algorithm : slightly better performances and redistribution of responsabilities.

Signed-off-by: BOUTIER Charly <[email protected]>

Author: EstherDarkish

src/components/graph/layout-utils.ts

@@ -0,0 +1,16 @@
+/**
+ * Copyright (c) 2025, RTE (http://www.rte-france.com)
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ */
+import { SecurityGroupMembersMap } from './layout.type';
+
+export function addMember(map: SecurityGroupMembersMap, key: string, member: string) {
+    const group = map.get(key);
+    if (group) {
+        group.push(member);
+    } else {
+        map.set(key, [member]);
+    }
+}