Change paste settings and add copyright headers

- There's now a notice reminding people to change the base URL if they
  had a custom base URL and change the paste type (that was something I
  personally had problems with when I was testing, so a reminder was
  helpful for me).

- Broke down some of the long lines on APIPage.cpp to be more readable.

- Added copyright headers where they were missing.

- Changed the paste service display names to the names they are more
  commonly known by.

- Changed the default hastebin base URL to https://hst.sh due to the
  acquisition of https://hastebin.com by Toptal.

launcher/ui/GuiUtil.cpp

@@ -1,3 +1,38 @@
+// SPDX-License-Identifier: GPL-3.0-only
+/*
+ *  PolyMC - Minecraft Launcher
+ *  Copyright (C) 2022 Lenny McLennington <lenny@sneed.church>
+ *
+ *  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/>.
+ *
+ * This file incorporates work covered by the following copyright and
+ * permission notice:
+ *
+ *      Copyright 2013-2021 MultiMC Contributors
+ *
+ *      Licensed under the Apache License, Version 2.0 (the "License");
+ *      you may not use this file except in compliance with the License.
+ *      You may obtain a copy of the License at
+ *
+ *          http://www.apache.org/licenses/LICENSE-2.0
+ *
+ *      Unless required by applicable law or agreed to in writing, software
+ *      distributed under the License is distributed on an "AS IS" BASIS,
+ *      WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *      See the License for the specific language governing permissions and
+ *      limitations under the License.
+ */
+
 #include "GuiUtil.h"
 
 #include <QClipboard>
@@ -16,7 +51,7 @@
 QString GuiUtil::uploadPaste(const QString &text, QWidget *parentWidget)
 {
     ProgressDialog dialog(parentWidget);
-    auto pasteTypeSetting = static_cast<PasteUpload::PasteType>(APPLICATION->settings()->get("PastebinType").toUInt());
+    auto pasteTypeSetting = static_cast<PasteUpload::PasteType>(APPLICATION->settings()->get("PastebinType").toInt());
     auto pasteCustomAPIBaseSetting = APPLICATION->settings()->get("PastebinCustomAPIBase").toString();
     std::unique_ptr<PasteUpload> paste(new PasteUpload(parentWidget, text, pasteCustomAPIBaseSetting, pasteTypeSetting));