Serialize midi events using vectors

Easier than to implement C-style arrays in Bitsery and this way we also
don't have to worry about cleanup.

Serum still segfaults with multiple events so something is still off.

src/common/logging.cpp

@@ -161,8 +161,8 @@ void Logger::log_event(bool is_dispatch,
             overload{
                 [&](const std::nullptr_t&) { message << "<nullptr>"; },
                 [&](const std::string& s) { message << "\"" << s << "\""; },
-                [&](const VstEvents& events) {
-                    message << "<" << events.numEvents << " midi_events>";
+                [&](const DynamicVstEvents& events) {
+                    message << "<" << events.events.size() << " midi_events>";
                 },
                 [&](const NeedsBuffer&) { message << "<writable_buffer>"; }},
             payload);