Core qt module for libs (#6278)

* Move logger and key signals from libcockatrice_utility to Cockatrice.

Took 9 minutes

* Only link Qt::Core instead of COCKATRICE_QT_MODULES to libraries, if possible.

Took 2 minutes

---------

Co-authored-by: Lukas Brübach <Bruebach.Lukas@bdosecurity.de>

cockatrice/src/interface/logger.h

@@ -0,0 +1,72 @@
+/**
+ * @file logger.h
+ * @ingroup Core
+ * @brief TODO: Document this.
+ */
+
+#ifndef LOGGER_H
+#define LOGGER_H
+
+#include <QFile>
+#include <QMutex>
+#include <QString>
+#include <QTextStream>
+#include <QVector>
+
+#if defined(Q_PROCESSOR_X86_32)
+#define BUILD_ARCHITECTURE "32-bit"
+#elif defined(Q_PROCESSOR_X86_64)
+#define BUILD_ARCHITECTURE "64-bit"
+#elif defined(Q_PROCESSOR_ARM)
+#define BUILD_ARCHITECTURE "ARM"
+#else
+#define BUILD_ARCHITECTURE "unknown"
+#endif
+
+class Logger : public QObject
+{
+    Q_OBJECT
+public:
+    static Logger &getInstance()
+    {
+        static Logger instance;
+        return instance;
+    }
+
+    void logToFile(bool enabled);
+    void log(QtMsgType type, const QMessageLogContext &ctx, const QString &message);
+    QString getClientVersion();
+    QString getClientOperatingSystem();
+    QString getSystemArchitecture();
+    QString getSystemLocale();
+    QString getClientInstallInfo();
+    QList<QString> getLogBuffer()
+    {
+        return logBuffer;
+    }
+
+private:
+    Logger();
+    ~Logger() override;
+    // Singleton - Don't implement copy constructor and assign operator
+    Logger(Logger const &);
+    void operator=(Logger const &);
+
+    bool logToFileEnabled;
+    QTextStream fileStream;
+    QFile fileHandle;
+    QList<QString> logBuffer;
+    QMutex mutex;
+
+protected:
+    void openLogfileSession();
+    void closeLogfileSession();
+
+protected slots:
+    void internalLog(const QString &message);
+
+signals:
+    void logEntryAdded(const QString &message);
+};
+
+#endif