Move the qt models to their own folder

Felt like the src folder was getting a bit crowded so move all the models to a folder named models.

src/models/userfiltermodel.h

@@ -0,0 +1,42 @@
+// SPDX-FileCopyrightText: 2022 James Graham <james.h.graham@protonmail.com>
+// SPDX-License-Identifier: GPL-2.0-only OR GPL-3.0-only OR LicenseRef-KDE-Accepted-GPL
+
+#pragma once
+
+#include <QSortFilterProxyModel>
+
+/**
+ * @class UserFilterModel
+ *
+ * This class creates a custom QSortFilterProxyModel for filtering a users by either
+ * display name or matrix ID. The filter can accept a full matrix id i.e. example:kde.org
+ * to separate between accounts on different servers with similar names.
+ */
+class UserFilterModel : public QSortFilterProxyModel
+{
+    Q_OBJECT
+
+    /**
+     * @brief This property hold the text of the filter.
+     *
+     * The text is either a desired display name or matrix id.
+     */
+    Q_PROPERTY(QString filterText READ filterText WRITE setFilterText NOTIFY filterTextChanged)
+
+public:
+    /**
+     * @brief Custom filter function checking boith the display name and matrix ID.
+     *
+     * @note The filter cannot be modified and will always use the same filter properties.
+     */
+    bool filterAcceptsRow(int sourceRow, const QModelIndex &sourceParent) const override;
+
+    QString filterText() const;
+    void setFilterText(const QString &filterText);
+
+Q_SIGNALS:
+    void filterTextChanged();
+
+private:
+    QString m_filterText;
+};