Added hex labeling option to graphs in flowview and frame info windows, a few tweaks for potential QT6 support

qcpaxistickerhex.cpp

@@ -0,0 +1,8 @@
+#include <Qt>
+#include "qcpaxistickerhex.h"
+
+QString QCPAxisTickerHex::getTickLabel (double tick, const QLocale &locale, QChar formatChar, int precision)
+{
+    int64_t hexVal = static_cast<int64_t>(tick);
+    return QString::number(hexVal, 16);
+}