Remove unused old model stuff

TODO.md

@@ -2,7 +2,6 @@
 
 - add account number binds
 
-- remove  `import QtQml.Models 2.12`s
 - fix left rooms opacity
 - fix escape keybinds (filter rooms, message selection)
 - fix python getting stuck when loading large room

src/gui/Base/HStringFilterModel.qml

@@ -1,20 +0,0 @@
-// SPDX-License-Identifier: LGPL-3.0-or-later
-
-import QtQuick 2.12
-import QtQml.Models 2.12
-
-HFilterModel {
-    model: sourceModel
-    acceptItem: item => utils.filterMatches(filter, item[field])
-    onFilterChanged: refilterAll()
-
-
-    property string field: "id"
-    property string filter: ""
-    property ListModel sourceModel
-
-    readonly property Connections sourceModelConnections: Connections {
-        target: sourceModel  // model is non-notifiable
-        onFieldsChanged: if (field in changes) refilterAt(index)
-    }
-}

src/gui/MainPane/RoomList.qml

@@ -2,7 +2,6 @@
 
 import QtQuick 2.12
 import QtQuick.Layouts 1.12
-import QtQml.Models 2.12
 import Qt.labs.qmlmodels 1.0
 import ".."
 import "../Base"