[qt] refactor: qt_common lib (#94)

This is part of a series of PRs made in preparation for the QML rewrite. this PR specifically moves a bunch of utility functions from main.cpp into qt_common, with the biggest benefit being that QML can reuse the exact same code through ctx passthrough.

Also, QtCommon::Frontend is an abstraction layer over several previously Widgets-specific stuff like QMessageBox that gets used everywhere. The idea is that once QML is implemented, these functions can have a Quick version implemented for systems that don't work well with Widgets (sun) or for those on Plasma 6+ (reduces memory usage w/o Widgets linkage) although Quick from C++ is actually anal, but whatever.

Other than that this should also just kinda reduce the size of main.cpp which is a 6000-line behemoth rn, and clangd straight up gives up with it for me (likely caused by the massive amount of headers, which this DOES reduce).

In the future, I probably want to create a common strings lookup table that both Qt and QML can reference--though I'm not sure how much linguist likes that--which should give us a way to keep language consistent (use frozen-map).

TODO: Docs for Qt stuff

Co-authored-by: MaranBr <maranbr@outlook.com>
Reviewed-on: https://git.eden-emu.dev/eden-emu/eden/pulls/94
Reviewed-by: MaranBr <maranbr@eden-emu.dev>
Reviewed-by: Shinmegumi <shinmegumi@eden-emu.dev>

src/qt_common/qt_progress_dialog.h

@@ -0,0 +1,47 @@
+// SPDX-FileCopyrightText: Copyright 2025 Eden Emulator Project
+// SPDX-License-Identifier: GPL-3.0-or-later
+
+#ifndef QT_PROGRESS_DIALOG_H
+#define QT_PROGRESS_DIALOG_H
+
+#include <QWindow>
+
+#ifdef YUZU_QT_WIDGETS
+#include <QProgressDialog>
+#endif
+
+namespace QtCommon::Frontend {
+#ifdef YUZU_QT_WIDGETS
+
+using QtProgressDialog = QProgressDialog;
+
+// TODO(crueter): QML impl
+#else
+class QtProgressDialog
+{
+public:
+    QtProgressDialog(const QString &labelText,
+                     const QString &cancelButtonText,
+                     int minimum,
+                     int maximum,
+                     QObject *parent = nullptr,
+                     Qt::WindowFlags f = Qt::WindowFlags());
+
+    bool wasCanceled() const;
+    void setWindowModality(Qt::WindowModality modality);
+    void setMinimumDuration(int durationMs);
+    void setAutoClose(bool autoClose);
+    void setAutoReset(bool autoReset);
+
+public slots:
+    void setLabelText(QString &text);
+    void setRange(int min, int max);
+    void setValue(int progress);
+    bool close();
+
+    void show();
+};
+#endif // YUZU_QT_WIDGETS
+
+}
+#endif // QT_PROGRESS_DIALOG_H