chore(UserListPanel): speed up sorting by removing ExpressionRole

- for sorting purposes, we can achieve the same effect with a simple
`JoinRole` instead

Iterates: #11059

storybook/pages/UserListPanelPage.qml

@@ -45,7 +45,7 @@ SplitView {
     // mainModuleInst mock
     QtObject {
         function getContactDetailsAsJson(publicKey, getVerificationRequest) {
-            return JSON.stringify({ ensVerified: false })
+            return JSON.stringify({ ensVerified: publicKey === "0x04d1bed192343f470f1255" }) // make Richard "ENS verified"
         }
         Component.onCompleted: {
             Utils.mainModuleInst = this
@@ -66,7 +66,7 @@ SplitView {
 
             sourceComponent: UserListPanel {
                 usersModel: model
-                label: "Some label"
+                label: "Members"
             }
         }
     }

ui/app/AppLayouts/Chat/panels/UserListPanel.qml

@@ -90,13 +90,10 @@ Item {
             model: SortFilterProxyModel {
                 sourceModel: root.usersModel
 
-                proxyRoles: FastExpressionRole {
-                    function displayNameProxy(nickname, ensName, displayName, aliasName) {
-                        return ProfileUtils.displayName(nickname, ensName, displayName, aliasName)
-                    }
+                proxyRoles: JoinRole {
                     name: "preferredDisplayName"
-                    expectedRoles: ["localNickname", "ensName", "displayName", "alias"]
-                    expression: displayNameProxy(model.localNickname, model.ensName, model.displayName, model.alias)
+                    roleNames: ["localNickname", "ensName", "displayName", "alias"]
+                    separator: ""
                 }
 
                 sorters: [