EventLoaderEUDAQ2: make string comparison for detector_name == plane_name case-insensitive

In the [EventLoaderEUDAQ2] we're comparing the name the current detector to each plane name. This requires the detectors to be named according to the following convention: <sensor_type>_<int>.

        // Concatenate plane name according to naming convention: sensor_type + "_" + int
        auto plane_name = plane.Sensor() + "_" + std::to_string(i_plane);
        if(m_detector->name() != plane_name) {
            LOG(DEBUG) << "Wrong plane: " << m_detector->name() << "!=" << plane_name << ". Continue.";
            continue;
        }

It can easily happen that you're mixing up the spelling of something like ATLASpix and ATLASPix, only one of which works and the other fails. I think this should be avoided by making the string comparison here case-insensitive.