refactor: split out setting api headers for downloads

Signed-off-by: Rachel Powers <508861+Ryex@users.noreply.github.com>

launcher/net/HeaderProxy.h

@@ -0,0 +1,49 @@
+// SPDX-License-Identifier: GPL-3.0-only
+/*
+ *  Prism Launcher - Minecraft Launcher
+ *  Copyright (c) 2022 flowln <flowlnlnln@gmail.com>
+ *  Copyright (C) 2022 Sefa Eyeoglu <contact@scrumplex.net>
+ *  Copyright (C) 2023 Rachel Powers <508861+Ryex@users.noreply.github.com>
+ *
+ *  This program is free software: you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation, version 3.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ *
+ */
+
+#pragma once
+
+#include <QNetworkRequest>
+
+namespace Net {
+
+struct HeaderPair {
+    QByteArray headerName;
+    QByteArray headerValue;
+};
+
+class HeaderProxy {
+   public:
+    HeaderProxy(){};
+    virtual ~HeaderProxy(){};
+
+   public:
+    virtual QList<HeaderPair> headers(const QNetworkRequest& request) const = 0;
+
+   public:
+    void writeHeaders(QNetworkRequest& request) {
+        for (auto header : headers(request)) {
+            request.setRawHeader(header.headerName, header.headerValue);
+        }
+    };
+};
+
+}  // namespace Net