fix(mentions): fix wrong user list given to mentions model (#16656)

Fixes #16602

This was broken when we refactored the members to use a single model for public channels. Those public channels then didn't have any members in their model they used for suggestions.
This is fixed by putting the logic in the UsersStore and reusing that store whenever we need a list of the members.

ui/app/AppLayouts/Chat/stores/UsersStore.qml

@@ -3,9 +3,21 @@ import QtQuick 2.15
 QtObject {
     id: root
 
+    property var chatCommunitySectionModule
+    property var chatDetails
     property var usersModule
 
-    readonly property var usersModel: usersModule ? usersModule.model : null
+    readonly property var usersModel: {
+        if (!chatDetails && !chatCommunitySectionModule) {
+            return null
+        }
+        let isFullCommunityList = !chatDetails.requiresPermissions
+        if (chatDetails.belongsToCommunity && isFullCommunityList && !!chatCommunitySectionModule) {
+            // Community channel with no permisisons. We can use the section's membersModel
+            return chatCommunitySectionModule.membersModel
+        }
+        return usersModule ? usersModule.model : null
+    }
     readonly property var temporaryModel: usersModule ? usersModule.temporaryModel : null
 
     function appendTemporaryModel(pubKey, displayName) {

ui/app/AppLayouts/Chat/views/ChatColumnView.qml

@@ -104,6 +104,8 @@ Item {
 
         readonly property ChatStores.UsersStore activeUsersStore: ChatStores.UsersStore {
             usersModule: !!d.activeChatContentModule ? d.activeChatContentModule.usersModule : null
+            chatDetails: !!d.activeChatContentModule ? d.activeChatContentModule.chatDetails : null
+            chatCommunitySectionModule: root.rootStore.chatCommunitySectionModule
         }
 
         readonly property ChatStores.MessageStore activeMessagesStore: ChatStores.MessageStore {

ui/app/AppLayouts/Chat/views/ChatContentView.qml

@@ -43,7 +43,9 @@ ColumnLayout {
 
     property var emojiPopup
     property var stickersPopup
-    property UsersStore usersStore: UsersStore {}
+    property UsersStore usersStore: UsersStore {
+        chatCommunitySectionModule: root.rootStore.chatCommunitySectionModule
+    }
 
     signal openStickerPackPopup(string stickerPackId)
 
@@ -65,6 +67,7 @@ ColumnLayout {
     spacing: 0
 
     onChatContentModuleChanged: if (!!chatContentModule) {
+        root.usersStore.chatDetails = root.chatContentModule.chatDetails
         root.usersStore.usersModule = root.chatContentModule.usersModule
     }
 

ui/app/AppLayouts/Chat/views/ChatView.qml

@@ -177,22 +177,18 @@ StatusSectionLayout {
     rightPanel: Component {
         id: userListComponent
         UserListPanel {
+            readonly property var usersStore: ChatStores.UsersStore {
+                usersModule: !!root.chatContentModule ? root.chatContentModule.usersModule : null
+                chatDetails: !!root.chatContentModule ? root.chatContentModule.chatDetails : null
+                chatCommunitySectionModule: root.rootStore.chatCommunitySectionModule
+            }
+
             anchors.fill: parent
             store: root.rootStore
             utilsStore: root.utilsStore
             label: qsTr("Members")
             communityMemberReevaluationStatus: root.rootStore.communityMemberReevaluationStatus
-            usersModel: {
+            usersModel: usersStore.usersModel
-                if (!root.chatContentModule || !root.chatContentModule.chatDetails) {
-                    return null
-                }
-                let isFullCommunityList = !root.chatContentModule.chatDetails.requiresPermissions
-                if (root.chatContentModule.chatDetails.belongsToCommunity && isFullCommunityList) {
-                    // Community channel with no permisisons. We can use the section's membersModel
-                    return root.rootStore.chatCommunitySectionModule.membersModel
-                }
-                return root.chatContentModule.usersModule ? root.chatContentModule.usersModule.model : null
-            }
         }
     }