fix(qrc): correct QML resource paths for AUR and release builds

The QML refactor in 1.0.4 used prefix /qml with file paths like
qml/Main.qml, embedding resources at qrc:/qml/qml/Main.qml while
main.cpp loads qrc:/qml/Main.qml. Use prefix / so paths match.

Also derive the displayed app version from CMake PROJECT_VERSION and
add a qrc_resources_test to prevent this regression in CI.

src/main.cpp

@@ -25,7 +25,7 @@ int main(int argc, char *argv[])
     QApplication::setApplicationName(QStringLiteral("BearWave"));
     QApplication::setDesktopFileName(QStringLiteral("de.nerdbear.bearwave"));
     QApplication::setOrganizationName(QStringLiteral("BearWave"));
-    QApplication::setApplicationVersion(QStringLiteral("1.0.5"));
+    QApplication::setApplicationVersion(QStringLiteral(BEARWAVE_VERSION));
 
     QApplication app(argc, argv);