Incorrect parsing of `mds::event_tag`

[lmichaelis]

Testing locally: game hangs at loading. Context:

// model_script.cc : make_event_tag
case mds::event_tag_type::window: {  // evt.type == mds::event_tag_type::dam_multiply
    auto frames = a.value_or(""); // "1.0"
    std::istringstream stream {frames};

    int32_t fr = 0;
        while (!stream.eof()) { // fails to parse string, before eof
        stream >> fr;
        evt.frames.push_back(fr);
    }

So 2 issues here:

• From what I know dam_multiply should not have frames, - just single value
• Input sanitation - probably should look forward to move away from stringstream

https://github.com/Try/OpenGothic/issues/483#issuecomment-1629756309