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/customemojimodel.h

@@ -0,0 +1,57 @@
+// SPDX-FileCopyrightText: 2021 Carson Black <uhhadd@gmail.com>
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+#pragma once
+
+#include <QAbstractListModel>
+#include <QRegularExpression>
+#include <memory>
+
+struct CustomEmoji {
+    QString name; // with :semicolons:
+    QString url; // mxc://
+    QRegularExpression regexp;
+
+    Q_GADGET
+    Q_PROPERTY(QString unicode MEMBER url)
+    Q_PROPERTY(QString name MEMBER name)
+};
+
+class CustomEmojiModel : public QAbstractListModel
+{
+    Q_OBJECT
+
+public:
+    enum Roles {
+        Name = Qt::DisplayRole,
+        ImageURL,
+        ModelData, // for emulating the regular emoji model's usage, otherwise the UI code would get too complicated
+        MxcUrl = 50,
+        DisplayRole = 51,
+        ReplacedTextRole = 52,
+        DescriptionRole = 53, // also invalid, reserved
+    };
+    Q_ENUM(Roles);
+
+    static CustomEmojiModel &instance()
+    {
+        static CustomEmojiModel _instance;
+        return _instance;
+    }
+
+    QVariant data(const QModelIndex &idx, int role = Qt::DisplayRole) const override;
+    int rowCount(const QModelIndex &parent = QModelIndex()) const override;
+
+    QHash<int, QByteArray> roleNames() const override;
+
+    Q_INVOKABLE QString preprocessText(const QString &it);
+    Q_INVOKABLE QVariantList filterModel(const QString &filter);
+    Q_INVOKABLE void addEmoji(const QString &name, const QUrl &location);
+    Q_INVOKABLE void removeEmoji(const QString &name);
+
+private:
+    explicit CustomEmojiModel(QObject *parent = nullptr);
+    QList<CustomEmoji> m_emojis;
+
+    void fetchEmojis();
+};